Miscellaneous. 233 



more decided difference from the continuous open groove at the floor 

 of the orbit in the adult female Tr. niger than that groove presents 

 in comparison with the shorter and shallower one in Trogl. Gorilla. 

 I find too that the second character of Trogl. Gorilla pointed out by 

 Prof. Agassiz, — " from the internal walls of the orbits which recede 

 from each other in descending towards the floor, thus leaving a large 

 pyramidal space for the lodgment of the os ethmo'ides," — is so much 

 less marked in the female skull of Tr. Gorilla, as contrasted with that 

 of Tr. niger, as to induce me to view it more in the light of a sexual 

 than a specific modification. 



The seventh is a good character, and is repeated by each of the 

 skulls of Tr. Gorilla examined by me. All the skuU^of Tr. niger also 

 show the backward projecting point, where the emargination exists 

 in TV. Gorilla. 



8. The minor relative projection of the incisive alveoli beyond the 

 line of the rest of the face is as characteristic of the three skulls of 

 Tr. Gorilla now in England as of the four in the United States, and 

 results from the same comparative shortness of the premaxillary 

 bones, between the nasal orifice and the edge of the incisive alveoli. 

 But the ossa nasi, besides being more narrow and compressed supe- 

 riorly, are more prominent at that part in TV. Gorilla than in Tr. niger, 

 and they are also more expanded and broader inferiorly, and I cannot 

 but regard the most decisive mark of the specific distinction of the 

 Troglodytes Gorilla to be the longer persistence of the maxillo-pre- 

 maxillary sutures, and the evidence thereby given of the peculiar 

 form, development and connexions of the upper portions of the pre- 

 maxillary bones. It is remarkable indeed, since these sutures remain 

 so distinct in the adult female skull (fig. 2) and the younger adult 

 male skull (fig. 1) here described, that no trace of them should have 

 been detected in any of the four skulls taken by Dr. Savage to 

 America, in which Dr. Wyman describes the ossa nasi as being 

 *' firmly co-ossified with each other and with the surrounding bones.' 



The triangular expanded facial part of the upper end of each pre- 

 maxillary intervening between the nasal and maxillary bones will 

 always serve to distinguish the cranium of an immature Trogl. Gorilla 

 from that of a Trogl. niger. 



MISCELLANEOUS. 



Note on the Development and Organization of Infusoria: — Gyratory 

 Movements of the Vitellus : Pulsations of the Contractile Vesicle in 

 the Egg. By M. F. Pouchet*. 



I HAVE followed out the development of several animalcules : some 

 emerge from the ovum with the form they are destined to present 

 during the whole course of their existence {Kerona, Vorticella) \ others 

 undergo, in the course of development, very apparent metamorphoses 



* Communicated by J. T. Arlidge, A.B., M.B. 



