236 



MR. G. E. DOBSON ON CAPROMYS MELANURUS. [Apr. 1, 



basioccipital and basisphenoid bones, and between tbe parietals. 

 Those of C. prehensilis and C. melanurus, though apparently adult, 

 do not show tbe sagittal crest, as above noted, and their surfaces are 

 altogether smoother; this may be due to sex, for the skull of C. 

 melanurus is that of a female, and that of the other species may 

 also belong to the same sex. The skulls of C. prehensilis and C. 

 brachyurus are in the British-Museum collection, that of C.pilorides 

 in the Hunterian Museum, while that of C. melanurus belongs to the 

 specimen of which the measurements of the body are given above. 



I. Myology. 



Muscles of the Head and Neck. 

 Sterno-faciales (fig. 1, st.f). — On reflecting the integument 





Dissection (balf natural size) of the pectoral and cervical muscles described 



in the text. 



a. Acromion; c. Clavicle; c.p. Coronoid process; e.a.m. External auditory 

 meaius; e.j.v. External juyidar vein; m-m'. Masseter; s.y Submaxillary 

 gland. 



covering the under surface of the neck and thorax these large 

 muscles come iuto view. They arise together from the centre line 



