510 Miscellaneous. 



between the fossil humerus and that of Phoccena, Prof. Huxley 

 named the species Phoccenopsis Mantelli. Mr. W. Mantell, F.G.S., 

 to whom the author was indebted for the opportunity of examining 

 these bones, stated that the beds whence they were obtained were 

 certainly of Tertiary age, and of much earlier date than the epoch 

 of the Dinornis, which he considered to have been contemporaneous 

 with man. The Palceudyptes was from an older bed than the 

 PhoccBnopsis. 



Prof. Huxley drew attention to the remarkable fact that a genus 

 so closely allied to the Penguins which now inhabit New Zealand, 

 and are entirely confined to the Southern Hemisphere, should have 

 existed at so remote an epoch in the same locality. 



4. "On the Dermal Armour of Crocodilus Hastingsice." By 

 Thomas H. Huxley, F.R.S., Sec. G.S., Prof, of Natural History, 

 Government School of Mines. 



The author, after briefly mentioning the very complete armour of 

 articulated dorsal and ventral scutes which he had recently discovered 

 (and described before the Linnaean Society) in two of the three 

 living genera of Alligatoridce, viz. Caiman and Jacure, showed that 

 similar scutes are found associated with the remains of Crocodilus 

 HastingsicB, a very fine skull and some scutes of which reptile, from 

 Hordwell, kindly lent to Prof. Huxley by Mr. S. Laing. F.G.S., 

 were exhibited. With respect to the suggestion of Prof. Owen, 

 that the Alligator Hantoniensis might possibly be a variety of Croco- 

 dilus Hastingsice, the author stated that he had observed in several 

 specimens of the recent Crocodilus palustris, which by its straight 

 premaxillo-maxillary suture and the general form of its skull most 

 nearly approaches C. Hastingsice, a tendency to assume the Alligator 

 character of a pit, instead of a groove, for the reception of the man- 

 dibular canine. Sometimes there is a pit on one side and a groove 

 on the other, and sometimes incomplete pits on both sides in this 

 Crocodile. Crocodilus Hastingsia still more nearly approaches the 

 Alligatoridce in the number of its teeth and in the characters of the 

 dermal armour now described ; so that the probability of its occa- 

 sionally assuming the AUigatorian dental pits on both sides is greatly 

 increased. 



MISCELLANEOUS. 



On the Difficulty of defining the Species of Mollusca. 

 By Dr. J. E. Gray, F.R.S. &c. 



In a former notice, I showed two instances where two specimens 

 of European terrestrial Mollusca, which so greatly resemble one an- 

 other as in each case to be regarded by most recent authors as only 

 slight varieties of the same species, proved, by the examination of 

 their teeth, to be very distinct species — so distinct that they must 

 have very different habits and manners. 



The paper by Mr. Hancock on the organization of the Bracbiopoda, 



