ANATOMY OF CACOPUS SYSTOMA. 527 



27. Notes on the Anatomy of Cacopus sy stoma, an Indian 

 Toad of the Family Engystomatidse. By D. W. 

 Devanesen, M.A.* 



[Received April 4, 1922 : Read May 9, 1922.] 



(Text-figm-es 1-19.) 



Contents. 



Page 



1. Introduction 527 



2. Thp Viscera 528 



3. Snb-cutaueous and other Fat-bodies 530 



4. Discussion on "the stout shape" of Cacopus systoma ... 531 



5. The Axial Skeleton 533 



6. The Appendicular Skeleton 536 



7. The Musculature 544 



8. Summary ; 553 



9. Key-list of certain abbreviations not explained along with 



Text-figures 555 



10. References to Literature 555 



1. Introduction. 



Cacopus systoma is an Indian toad of the narrow-mouthed, 

 edentulous and fossorial type belonging to the family Engy- 

 stomatidae, well-known for their habit of feeding upon ants and 

 termites. Among the chief characters which distinguish the 

 genus are the following : the palate has two dermal transverse 

 folds more or less denticulated, one behind the vomers and the 

 other in front of the oesophagus ; there are no pre-coracoids ; the 

 sternum is a large cartilaginous plate ; and the transverse pro- 

 cesses of the sacral vertebra are rather strongly dilated. 



The following notes were compiled in India during what was 

 intended to be a comprehensive study of the morphology of 

 Cacopus systoma. Comparisons with the anatomy of certain 

 other toads of the same family and comments thereon have been 

 made wherever suitable. 



This work was done in the Zoological Laboratory of the Madras 

 Christian College, Madras. Grateful acknowledgment is hereby 

 made for suggestions and advice to Prof. W. Rae Sherifi's of the 

 college mentioned, and to Dr. J. R. Henderson, F.L.S., formerly 

 Superintendent of the Government Museum, Madras. To Prof. 

 MacBride's encouragement the communication of this paper is 

 due ; for this and for reading the manuscript, I thank him. 



* Communicated by Prof. E. W. MacBeide, D.Sc, LL.D., F.R.S., F.Z.S. 



