30 



As a doubt had arisen as to the distinction of this species from the 

 Hemione, Equus Hetniojius, of Kutch, I have compared these skulls 

 with the skull of the latter belonging to an imperfect skeleton, which 

 was kindly presented to the Museum, with the skin, by the Earl of 

 Derby, from an animal which lived some time in Knowsley Park. 



The forehead of all the three specimens of E. Kiang is rather con- 

 vex between the eyes, and the centre of the face is narrow and keeled 

 on the sides ; while in the skull of E. Hemionus the forehead is flat 

 between the eyes, and the centre line of the face is rather broader and 

 rounded gradually off on the sides, and the incisive bone is longer and 

 more gradually arched, making the incisor more perpendicular in the 

 latter than in any of the former. 



But the most distinctive character between the four skulls is in the 

 position of the infraorbital foramen. In E. Hemionus it is high up, 

 about one-third the space between the face-line and the back edge of 

 the teeth ; it is far back, being directly over the front end of the cheek- 

 ridge and the back edge of the third grinder : while in all the three 

 specimens of the skulls of E. Kiang this foramen is lower down, being 

 nearly in the centre of the space between the face-line and the base 

 of the teeth, and it is placed in a line over the back edge of the second 

 grinder, some distance in front of the end of the cheek-ridge. 



The under surface of the body of the posterior sphenoid is narrow 

 and convex in E. Hemionus, and broad and flat in E. Kiang. The 

 vomer is much more compressed in the latter than in the E. Hemionus. 



I am not certain that the distinctions here described may be suffi- 

 cient to show that these two animals are separate species, but they 

 indicate the necessity of the subject being more fully examined. 



In the position of the suborbital foramen the E. Kiang more nearly 

 resembles the E. asinus, and the E. Hemionus that of E. Zebra and 

 E. Burchellii. 



Two of the skulls of the E. Kiang show the small rudimentary 

 grinder in front of the other ; but this tooth is to be more or less di- 

 stinctly observed in the skulls of the other Equidce in the Museum 

 collection. I may observe, that in the skull of Equus Burchellii in 

 the British Museum collection, this tooth is placed on the inner side 

 of the first true grinder. 



3. Description of the animal of Trigonia, from actual 

 DISSECTION. By G. Huxley, Esa., R.N., w^ith an intro- 

 ductory NOTE BY Professor E. Forbes, F.R.S. etc. etc. 



(MoUusca, PI. III.) 



The accompanjnng account of the animal of Trigonia was forwarded 

 to me by Mr. Huxley, Assistant-Surgeon to the Rattlesnake, now sur- 

 veying in the Eastern and Australian Seas, under the able command 

 and scientific zeal of Capt. Owen Stanley. 



The great number, beauty and geological importance of the species 

 of this interesting genus have made especially valuable a knowledge 

 of the structure of its animal. Quoy and Gaimard were the first to 

 give any account of it, and a figure and description of the animal of 



