HOMARUS AMERICANUS MILNE-EDWARDS 123 



FIG. 27. Astacus fluviatilis after Huxley. A, male; B, female; a, anus; 

 gg, opening of green gland (antennal gland, nephridium) ; Ib, upper lip or 

 labrum; mt, metastoma or under lip; od, opening of oviduct (9 gen. op.); 

 vd, opening of vasdeferens (cf gen. op.); i, stem of eye; 2, antennules; j, an- 

 tennae; 4, mandibles; 8, second maxillipeds; p, third maxillipeds; 10, first 

 pereiopod; u, second pereiopod; 14, fifth pereiopod; 15-20, abdominal ap- 

 pendages; X, XI, XIV, sternites of fourth, fifth, and eighth thoracic somites; 

 XVI, sternite of second abdominal somite. 



