On the Homologies of the Cephalopoda. 303 Leiocephalus aculeatus, sp. n. Two lateral carina? along the upper edge of the sides as well as the median dorsal one. Supraorbitals very broad, as in L. tridescenS) Gthr. Head as high as broad. Nostril posteriorly in an elongate nasal shield. Scales on the top of the muzzle numerous, polygonal, becoming larger towards the frontal region, where they pass into the two series of large interorbital plates, which are closely in contact. Three occipital plates — two rather large anterior, and one small posterior ; two parietals on each side, the posterior one being very large. Orbital canthus sharp. A single series of very broad supraorbitals bordered with some small scales on each side. Only one elongate scale on the canthus between the upper angle of the orbit and the nostril, there being two such scales in L. iridescens. Upper labials four, narrow, elongate ; a row of eight small scales above them ; two rows of frenals, with an elongate infraocular scale. Ear-opening about half as large as the eye. The scales are everywhere keeled, sharp and dagger-like, with projecting points. A median dorsal crest of erect triangular scales ex-tending on the tail ; a weaker lateral one on each side of the back. Tail long, compressed, nearly thrice the length of the body. Bronzed green, brownish on the sides, with vertical streaks. A white stripe from the ear to the fore limb, and another superiorly from the ear as far as the shoulder ; another white stripe descending from the lateral carina to the fore limb. millim. Distance of snout from eye 10 „ „ ear 23 „ „ fore limb 45 „ „ vent 100 Length of fore limb 50 „ third and fourth front toe 16 „ hind limb 85 „ fourth hind toe 25 Five specimens of the above described species were collected by Mr. Roff ; they are from Moyobamba, Peru. XXXIV. — On the Homologies of the Cephalopoda. By J. F. Blake, M.A., Lecturer on Comparative Anatomy at Charing-Cross Hospital. There are two points of interest in the relations of the Ce-phalopoda which cannot yet be said to be settled. The first
BioStor
