Fig. i8. — Crustacea-Malacostraca-Eucarida : male and female genitalia of a 

 crab, Callinectcs sapidus. 



A, the intromittent apparatus, including on each side the ijenis and the 

 modified first and second pleopods (gonopods), ventral view. B, base of left 

 first gonopod, posterior (under) surface. C, left second gonopod, posterior 

 (under) surface. D, left penis and base of left first gonopod, anterior (upper) 

 surface. E, ovary, dorsal view. F, gonopores of female on tenth (third thoracic ) 

 sternum. G, spermatheca of a young hard-shell female. H, spermatheca of a 

 soft-shell female probably ready for insemination. 



a, distal shaft of first gonopod ; b, bulblike base of telopodite of first gonopod ; 

 Bspd, basipodite ; c, anterior proximal forainen of first gonopod ; Cxpd, coxop- 

 odite; d, posterior distal foramen of first gonopod; Dct, spermathecal duct; 

 c, distal arm of second gonopod ; /, g, anterior and posterior articulations of 

 telopodite on coxopodite ; Gpr, gonopore ; gr, groove of first gonopod ; mh, 

 membrane ; Ov, ovary ; Pen, penis ; Spt, spermatheca ; XStn, sternum of genital 

 segment of female; XllCxpd, XlllCxpd, XlVCxpd, coxopodites of last pereio- 

 pods and of first and second pleopods (gonopods) ; 167, 168, coxal muscles of 

 telopodite; i6p, compressor muscle of bulb of first gonopod. 



