Zoology. — 743 
dred the Macruroid Corypheenoides gigas at a depth of 4255 
metres, and Alexiterion parfaiti, nov. gen. and sp. of Ophidiide 
The abyssal fish fauna seems to be in great part homogeneous. 
Bathysaurus, Halosaurus, Bathypterois, Macrurus, Coryphenoides, 
and many other genera are found both in the Atlantic and in the 
Pacific, and many species seem to have an extensive distribution. 
Thus Dicrolene introniger occurs near the North American coas 
and on those of the Soudan; Macrurus holotrachys Gunt., dis- 
covered at the mouth of the La Plata, has been dredged on the 
Maroccan coast; Stomias boa ‘of the Mediterranean has been taken 
in the Arctic Ocean, in the Atlantic, and in the Pacific; and the 
Talisman captured at the Azores, off the Soudan, and at the Cape 
erde Islands, a Macrurid which seems to be Macrurus juponicus 
eg. 
VACUITIES IN THE SKULLS oF Mammats.—Dr. D. D. Slade 
presents (Bulletin Mus. Comp. Zoology, XIII., 8) a comparative 
study of certain vacuities found in the macerated mammalian skull. 
, THE TEETH or SHErp.—Miss Florence Mayo has recently 
investigated (Bulletin Mus. Comp. Zool., xiii.) the question as to 
whether at any stage of development there occur germs of the 
superior canines and incisors in the sheep, a question upon which 
there were conflicting opinions. She finds that at a certain stage in 
the development of the embryo sheep the dental lamina exists 
throughout the incisor and canine regions and that in the latter an 
enamel organ is formed but nowhere is there a dentine germ. No 
enamel is ever formed and the organ soon disappears. From the 
standpoint of phylogeny Miss Mayo thinks that the disappearance 
of the teeth has been a progressive one, beginning with the middle 
incisors and gradually extending back. This has already been 
shown by palæontology. 
