Dr. Strahl on the Thalassinse. 459 
XLIX. — Supplement to a Memoir on the Thalassinse*. 
By Dr. STRAHLf. 
Amongst the reasons cited byDe Haan ('Fauna Japonica/ p. 160) 
in favour of the union of the Astacoidea and the Thalassinoidea, 
the relation of the simple branchia to the fifth pair of feet plays 
a not unimportant part. He states that although the Asta- 
coidea possess this single branchia, which is wanting in all Tha- 
lassinoidea, the genus Astacus itself belongs by its species to 
both sections, and efi^ects the union. Subsequently, however, 
Erichson divided the genus Astacus, employing for this purpose 
especially the characters of the branchiae ; so that, by this division 
into new genera, the separation of the Astacoidea and Thalas- 
sinoidea might appear to be again established. The genera 
Camharus and Cheraps, which are destitute of the branchia on 
the fifth pair of feet, and were therefore removed from the 
genus Astacus, nevertheless approach more closely to Astacus 
and its allies than to the Thalassinoidea. Cheraps even gives 
up another character of the Astacoidea, namely, the appendages; 
on the first segment of the abdomen in the male sex, which 
are likewise wanting in the genera Astacoides and Engceus, and 
makes another step towards the Thalassinoidea; nevertheless 
its relationship to Astacus and its allies is greater than to the 
Thalassinoidea. The common characters of the genera grouping 
themselves immediately about Astacus, besides the perfectly deve- 
loped antennal scale {armiger and squama), are, that the first three 
pairs of feet are didactyle, and the external lamina of the caudal 
fin transversely divided; the forehead bears a rostrum projecting 
over the eyes, beneath which the latter are concealed whenever 
the appearance of danger causes them to require protection. 
Here belong the genera, Homarus, Nephrops, Paranephrops, 
Astacus, Astacoides, Engceus, Camharus, and Cheraps. I propose 
to group these together as Astacina. 
Glaucothoe and Axius are not to be placed here, although 
they are stated to possess the antennal scale ; at any rate, they 
have fewer didactyle feet, and the outer lamina of the caudal fin 
is entire. In describing Axius plectrorhynchus, I have pointed 
out the difficulty which existed in determining whether this spe- 
cies does or does not possess a moveable scale. It now appears to 
me doubtful whether ^a?ms and Glaucothoe have a moveable scale, 
because the existence of this belongs to the general character of 
the Astacina, from which both these genera depart in several 
respects ; and, indeed, they cannot even be referred to a common 
• See 'Annals,' May 1862, p. 383. 
t Translated by W. S. Dallas, F.L.S., from the * Monatsber. der Akad. 
der Wiss. zu Berlin,' February 1862, p. 133. 
460 Dr. Strahl on the Thalassinse. 
group, but must decidedly be separated, as I will immediately 
show. Hitherto I have been unable to examine Axius sti- 
rhynchus and Glaucotho'e Peronii in connexion with the existence 
or absence of the moveable scale. Should it prove that these 
species possess only the armiger, Axius and Calocaris would 
probably have to be united ; for the latter has certainly no scale 
(see the figure in Bell's 'British Crustacea/ p. 233), and the 
other differences are not sufficient to support the division into 
two separate genera. 
That Gehia possesses no antennal scale is perfectly correct, 
although Dana thinks that his G. pugettensis might possess a 
scale. In G. barbata, described by me as new, the same struc- 
ture, however, occurs ; and I have pointed out that, great as the 
illusion may be, there is nothing but a fringe on the second 
joint, which, moreover, also occurs in G. litt oralis. I have even 
seen a specimen of G. barbata, of which the left external antenna 
exhibited the fringe uninjured, while on the right side the hairs 
of the fringe were rubbed ofi", so that no one could be misled 
into the assumption of a scale. In the same way probably the 
fringe of G. hirtifrons, White, as figured by Dana, has been de- 
stroyed, and the fringe belongs to the general generic character. 
Consequently Gebia is throughout destitute of all trace of a 
scale, and G. hirtifrons does not constitute the type of a series 
of GebicB unfurnished with fringes. 
The new genus Tr-ypaa is represented by Dana as allied to 
Callianassa. The structure of the external maxillipeds and of 
the five pairs of feet, and the configuration of the abdomen, 
especially in regard to the appendages, certainly agree in the 
two genera ; but- the eye-peduncles are difi'erent. In Trypeea^ 
according to Dana's own drawing, these are cylindrical with a 
terminal cornea ; but he expresses an opinion that they may be 
incorrect, as he could not make another comparison with nature. 
However, a further distinction is furnished by the structure of 
the outer antenna : as far as we can judge fi'om Dana's figure, 
this has neither squama nor armiger. Consequently the gap 
between Callianassa and Trypcsa would be greater than is stated 
by Dana. A second species, T. porcellana, has been described 
by Kinahan (' Journ. Boy. Soc. Dubl.' i. p. 130, pi. 4. fig. 2), 
but this is probably only a Callianassa ; for, to judge from the 
figure, the flagella of the inner antennae are rather long, and 
certainly longer than their third joint, which is in opposition to 
Dana's diagnosis; moreover he says of the eyes that they are 
sessile, but from the figure it is clear that they present the pecu- 
liar structure of Callianassa. The character of the external an- 
tennge cannot be determined with certainty from the figure. 
It is tru€i that all Thalassinoidea have no branchiae on the fifth 
Mr. F. P. Pascoe on some new Coleoptera. 4G1 
pair of feet, and that the outer lamina of the caudal fin is entire ; 
nevertheless, even here two perfectly different forras occur, for 
which the characteristic, distinguishing points of organization 
have yet to be ascertained. In many the first two pairs of feet 
are cheliferous, namely, Axius, Calocaris, Callianassa, Trypma, 
Scytoleptus, Callianidea, and Callisea; the others, Glaucothoe, 
Calliadne, Laomedia, Gehia, and Thalassina, have only the first 
pair of feet cheliferous, and these in the last two genera are even 
subcheliform. Taking into consideration the character of the 
outer antenna, Calocaris, Callianassa, and Thalassina may be 
united, as possessing only the armiger; Axius and Glaucothoe 
also probably belong here. There then remain Scytoleptus, 
Laomedia, Calliadne, Trypaa, Gehia, Callianidea, and Callisea, 
which possess neither squama nor armiger. 
Neither the characters of the cheliferous feet nor those of the 
external antennse, however, unite the genera most nearly allied 
in their external conformatioo ; but the relation of the pedun- 
culated eyes to the forehead and its process furnishes a more 
accordant division. In Axius, Calocaris, Gebia, Scytoleptus, 
Laomedia, and Calliadne, the forehead projects beyond the eyes ; 
and the latter can be concealed under it, as in the Astacina. 
We name this group Gehiina. The others, namely, Glaucothoe, 
Callianassa, Thalassina, Trypcea, Callianidea, and Callisea, have 
no such projecting forehead, and their eyes lie free in front of it. 
This latter group we may name Thalassinina. 
The Astacida, consequently, split up into Astacina, Gehiina, 
and llialassinina. 
L. — On some new Coleoptera from Lizard Island, North-eastern 
Australia. By Francis P. Pascoe, F.L.S. &c. 
Lizard Island is one of the group forming the Great Barrier 
lleef on the north-east coast of Australia, in (about) 14<° S. lat., 
145° E. long. ; but it is so small that its name is only to be found 
on the larger maps. Calculating in a rough way, it may be 
about 200 miles south and a little east of Cape York, the northern 
extremity of the continent. 
The collection which is the subject of this paper was formed 
by Mr. Macgillivray, and is a small one, so far as the number of 
species is concerned; but if, as is probable, it was obtained 
during the casual stay of his ship for water or wood (perhaps 
only a few hours), the 700 specimens (mostly Coleoptera) which 
it contains indicate a greater amount of insect life than could 
have been anticipated. Of course a collection so formed cannot 
justify us in drawing any very definite conclusions ; but it is