222 Dr. A. Glinther on Ceratodus, Nauphceus viiliaris. PI. XVI. fig. 3. N. oblongo-obovatii3, niger, supra granulis nitidis nigro circumdatis confertim maculatus, interstitiis griseo-squamosis, medio protho-racis elytrorumque antice liiiea grisea notatis ; capite supra oculos dense squamoso, maculis duabus fuscis decorate ; rostro prothorace multo breviore, testaceo, subtiliter remote punctulato, basi squa-moso ; antennis testaceis ; prothorace pone apicem utrinque ma-cula obliqua nigra ; scutcllo distincto, orbiculari ; elytris lateribus modice rotundatis, basi pone scutellum paulo gibbosis, in medio dorsi utrinque perparum longitudinaliter excavatis, striato-pun-ctatis, interstitiis latis, vix convexis, confertim uniscriatim granu-latis, medio macula rotundata nigra ad suturam approximata, pla-gisque duabus oblongis margine externo, ornatis ; corpore infra femoribusquo dcnsissime eburneo-squamosis ; tibiis tarsisquc squamis filiformibus minus dense vestitis, his infra flavo-tomen-tosis. Long. 4i lin. Hah. Waigiou, Mysol. [To be continued.] XXV. — Ceratodiis, and its Place in the System. By Dr. Albert Gunther, F.E.S. The general external appearance of this most remarkable fish lias been described by Mr. Krcflft in Proc. Zool. Soc. 1870, p. 221. My observations* are based on tlrree specimens, viz. one without intestines, one fully developed male, and one female which does not appear to have attained to maturity. Differences in the number and microscopical structure of the scales seem to indicate the existence of a second species beside that described by Mr. Krefft as Ceratodus Forsteri. Its scales are considerably smaller and more numerous ; and it may be named Ceratodus miolejjis. The skeleton represents the type which is so well known from Owen's, Bischoff's, and Ilyrtl's descriptions of LejJido-siren and Protopterus. In certain points of detail, such as the arrangement of the bones of the skull, the form of the cerebral and acoustic cavities, the development of the first rib and apophyses generally, the structure of the scapular arch and pelvis, the resemblance of the genera named is perfect ; and from an examination of the skeleton alone the conclusi(in might have been drawn that they belong to the same natural * The following notes are a short resume of a memoir presented to the Eoyal Society at the beginning of last month, and containing a detailed description of the entire organization of Ceratodus, with the exception of the nervous system.