TRANSACTIONS OF SECTION D. 737 



7. On the Poison Apparatus of Certain Snakes. 

 By G. S. West, A.R.C.Sci. Lond. 



The author describes, in thirteen genera of Opisthoglypha, a gland, which, there 

 is every reason to believe, is homologous with the poison glaud of the Viperine 

 and Proteroglyphous types. The course of the poison duct and its detailed 

 relationships to the teeth are dealt with, the latter being established through the 

 mediation of a cavity enclosed within muscular folds, and so effected that loss of 

 the tooth does not in any way result in iojury to the duct. The distal portion of 

 the duct is shown to be secretory and mucus-forming. 



In the marine snakes (Hydrophiinre) the poison gland is shown to be more or 

 less free from the supra-labial, and to consist of longitudinally disposed tubules 

 converging anteriorly towards a central duct. The latter is shown to become 

 enlarged anteriorly, enclosing a cavity in front of the bases of the grooved teeth 

 having muscular walls and specialised for purpose of communication with the 

 grooves. 



Certain vascular folds of the buccal mucous membrane are described, which 

 occupy the interstices between the teeth, and are probably analogous to the 

 villous processes occurring in the mouths of certain soft-shelled Chelonians. 



8. On the Value of Myology as an Aid in the Classification of Animals. 

 By F. G. Parsons, F.R.C.S., Lecturer on Comparative Anatomy at 

 St. Thomas's Hospital. 



The paper contains a short notice of the reasons which induce Systematists to 

 place little reliance on the study of muscles. It then reviews some of the muscles 

 in the great order of Rodents, and points out how closely they correspond in 

 animals which are nearly related, and how little the different modes of life of their 

 possessors aft'ect them. The ease with which different sub-orders and families of 

 Rodents can be distinguished by a study of their muscles is next noticed, and 

 finally the test of myology is applied to the family of Dipodidae, the position of 

 which is still unsettled. 



9. On Ultimate Vital Units. By Miss Nina Layard. 



1895. 3 B 



