distomedian 

 projections 



I 



S anterior process; 



lateral lobe 

 „„„f ^ dorsolateral 



ventmmedian obule^,__ ^=;:;3'entro lateral 

 dorsomediarTi°°"'M ,-<:;;*^>'^:^::^^SX.Iobule 



dorsomediai^2^'^ll-;5i^ 

 lobule - Jf^^^V^*'^^^ 



I r 



at u 

 en L_ 



^°- median carina 



lateral plate 



sternite XIII 



sternite XIV 



horn of median^ ^^ * 

 protuberance 



seminal 

 receptacle 



Figure 3. — I>ature.s of the external genitalia used in Pciiarus taxonomy. Peta.snia : a. Cross section witli arrangement 

 of lobes, b. Distal portion, e. Tlielycum. d. Thelycum with lateral plate.s removed showing seminal receptacle and 

 position of horns of median protuberance. 



WESTERN ATLANTIC SHRIMPS OF GENUS PENAEVS 



465 



