VIII. 



THEEE ANATOMICAL NOTES AND TWO 

 ANATOMICAL QUERIES. 



The following points of anatomy, though of no very wide sig- 

 nificance, are nevertheless by no means devoid of interest, and are, 

 I believe, new : — 



i. The organs of Bojanus open into the pericardial space on 

 either side, in the floor of that space at a point between the outer 

 end of the auricle and the visceral mass in Ostrea and Pecten. It is 

 obvious that this orifice, which in other Lamellibranchiata is drawn 

 out into a funnel-shaped passage, is the representative of the 

 'pyriform vesicle ' of the nudibranchiate mollusca, for which see 

 Hancock, ' Linnaean Society's Transactions/ xxiv. p. 511 (1864). 



2. To distinguish the skull of a hare (Lepus timidus) from that 

 of a rabbit (Lepus cuniculus), several points of difference may be 

 employed. Perhaps the readiest, and, as I believe, the surest, is 

 the greater complexity of the maxillo-turbinal bones in the latter 

 animal. It is obvious that an animal living very usually in a 

 subterranean atmosphere is advantaged by having that atmosphere 

 warmed as much as possible before entering the lungs. 



3. Two of the subungulate rodents — viz. the guinea-pig (Cavia 

 aperea), as shown by Mr. Marshall ('Phil. Trans.' 1850, p. 151) ; 

 and the agouti (Dasyprocta aguti) — resemble the ungulata proper, 

 in having but a single vena cava superior. They differ from these 

 larger quadrupeds in possessing clavicles, though, it is true, incom- 

 plete ones. Coelogenys also — another of the subungulate rodents — 

 possesses clavicles. I should be much obliged to any of the readers 

 of the ' Journal of Anatomy and Physiology ' who would inform 

 me whether Coelogenys, Hydrockoerus, and Dolichotis have one or two 

 superior cavae, and whether the two last-named of the five Subungu- 

 lata are really entirely devoid of clavicles. 



