ASTACUS NIGRESCEXS. 



24i 



There are no cervical spines, and the middle part of 

 the cervical groove is angulated backwards instead of 



being transverse. 



I 



t 



V 



Fig, 62, A & D, Astacus torrcnt'mm ; B & E, >1, nohilis ; C & F, 



A. nigrcscens. A — C, 1st abdominal appendage of the male ; D — F, 



endopodite of second appendage ( x 3). a, anterior, and J, posterior rolled 



edge ; c, d, e, corresponding parts of the appendages in each species ; 



/, rolled plate of endopodite ; g, terminal division of endopodite. 



The abdominal plem'a are narrow, equal-sided, and 

 acutely pointed in the males (fig. 61, F) — slightly 

 broader, more obtuse, and with the anterior edges 



