14 
INDIAN TERTIARY AND POST-TERTIARY VERTEBRATA. 
E. quagga ; and they may also be detected in some skulls of E. caballus, where the 
groove occurring in advance of the infra-orbital foramen not unfrequently terminates 
above in a very shallow, but distinct de^^ression. 
The smooth form of these cavities in the Perim skull leaves little or no doubt 
that they once contained a sebaceous gland, like the ‘ larmier ’ of the deer and 
antelopes. In all deer and in most antelopes the larmier is single, and placed almost 
entirely in the lachrymal ; having of course no connection with the infra-orbital 
foramen. In some antelopes, however (e.g., Gephalopus maxivelli, and C. pygmceaf a 
similar cavity is present in the maxilla, which sometimes coexists with the lachrymal 
cavity, and sometimes replaces it. “In the African water-hogs \Potamochoerus~\ a 
naso-maxillary pit opens between the eye and snout, rather nearer the eye.”^ In 
Oreodo7i^ there is a single cavity which is confined to the lachrymal. 
These observations indicate pretty clearly that the maxillary cavities of 
Hippotlieriimi are homologous with those of the Artiodactyla ; and are very 
noteworthy as being one of the very feAV evidences among the later forms of an 
original connection between the artiodactyle and perissodactyle modifications of the 
Ungulata. 
The differences in the form of the posterior maxillary cavity in H. antilopinum, 
and U. gracile are so great as to leave no question of the sjDecific distinctness of 
those forms, of which, from the study of the remains then available, some doubt was 
entertained in the second volume. Tlie diminished size and more advanced 
position of the same cavity in H. antilopinum indicates that this species should be 
regarded as a form between the European species, and the modern horses ; of which 
the African species retain most traces of their connection with the hippotheres. If 
the writer’s memory serves him correctly, the posterior larmial caAuty in the young 
maxilla of H. theobaldi from the Punjab, briefly mentioned in the second volume,^ is 
of much larger size, and placed considerably nearer to the orbit than in the Perim 
skull. 
The latter does not appear to differ in any other important points from the 
European species. 
Distribution. — The specimen under consideration extends the range of the 
species to Perim Island ; of which there was only some doubtful evidence at the 
time of publication of the second volume. 
Species : non. det. {? nov.) 
Dpper molars. — In the accompanying woodcut (fig. 4) there are represented 
three associated right upper cheek-teeth of a species of Hippothcrium lately obtained 
1 See Owen, “Anatomy of Vertebrates,” vol. III., p. 633. 
2 Owen, op. cit., p. 634. 
3 Gaudry, “ Les Enchainements — Mam. Tert.,” fig, 90, p. 81. 
4 Page 83. The specimen is No. C. 153, Indian Museum ; and the present writer would be obliged to any oflSicer of the 
G. S. I. who would compare it with the figure of the Perim skull, and communicate the result to the “ Records.” 
