BY W. J. McKAY. 969 



the anterior suspensory ligament of the venom gland ; while it is 

 related by its inferior surface to the parieto-palatine muscle. The 

 gland does not project backwards out of the orbital fossa as in the 

 non-venomous forms; nor does the masseter muscle give any fibres 

 to act as a compressor, as we find in the non-venomous forms. 



The Labial Glands. 



The superior labial gland is represented by a number of fol- 

 licles placed along the superior labium. It meets its fellow of the 

 opposite side anteriorly, while it is continuous at the symphysis of 

 the lips with the inferior labial gland. This runs along the edge 

 of the inferior labium, and anteriorly meets its fellow of the 

 opposite side. 



Sublingual Glands. 



The anterior sublingual glands are two in number. They 

 are placed above the genio-hyo-glossus, and the inter-mandib- 

 ularis, and are immediately in front of the opening for the 

 tongue on the anterior portion of the floor of the mouth, into 

 which they open by numerous ducts. Posteriorly a muscular 

 band embraces the gland. This is derived from the inter-mandi- 

 bularis, and is called the " Vorwartszieher " of the gland by 

 Leydig (No. 16). A band of muscle proceeding from the posterior 

 extremity corresponds to his " Riickwartszieher." In Hydro- 

 saurus the whole of the inter-mandibularis is utilized in forming 

 a compressor for the large sublingual glands. A well marked 

 posterior sublingual is present immediately behind the anterior 

 ones. 



In comparing the relative state of development of the glands in 

 Acanthophis with the development in Mof^elia and other forms, we 

 have come to the same conclusions as Duvernoy (No. 5). 



He was the first to point out that, in the Aglyphodontians we 

 have the superior ^.nd inferior labial glands, as well as the lachry- 

 mal gland, very extensively developed. That in the Opisthogly- 

 phians we have the glands relatively smaller, and a venom 

 gland begins to be developed. In the Proteroglyhphians we have 



