884 



MR. F. E. BEDDARD OX THE 



[Nov. 26, 



The shortness of the sternum considered relatively to the length 

 of the sternum in other genera results in a much longer post- 

 sternal rectus abdominis, while the pectoralis appears to be short, 

 again relatively speaking. The second point of difference concerns 

 the course of the sheet of membranous tissue which separates the 

 abdominal from the pectoral lymph-space. In Xenoplirys and in 

 Megaloplirys nasuta this is almost transverse to the longitudinal 

 axis of the body, being slightly convex anteriorly ; it hardly 

 reaches the pectoralis abdominis. In Lejitohrachium, on the other 

 hand, the attachment of this membrane is V-shaped with the apex 

 of the V directed anteriorly ; it passes OA^er the pectoralis 

 abdominis to near the middle of which it is attached. 



Ventral musculature of LeptobracMum hasseUH. 

 Lettering as in text-fig. 231. 



However, in this genus, as in those already treated of, there 

 appears to be no pectoralis cutaneus. The jDectoralis anterior 

 seems to be exactly like that of XenojjJirys, and I could detect no 

 trace of a separate sternoradialis muscle. The jDectoralis posterior, 

 on the other hand, is not like that of Xenoplirys. For it arises 

 along a line which extends halfway down the bony style of the 



