FISHERY BULLETIN: VOL. 75, NO. 2 



gella incomplete in specimens examined; how- 

 ever, in Faxon's (1895) illustration both subequal, 

 about 1.25 times as long as carapace. Scaphocerite 

 overreaching antennular peduncle by as much as 

 0.3 of its own length, with lateral rib ending in 

 sharp, slender spine reaching, or overreaching, 

 distal margin of lamella. Mandibular palp extend- 

 ing to distal 0.3 of carpocerite; proximal article 

 about 2.6 times as long as wide. Third maxilliped 

 reaching beyond antennular peduncle by length 

 of dactyl and about 0.5 that of propodus; 

 length of dactyl about 0.65 that of propodus. 



First pereopod extending to distal end of carpo- 

 cerite or overreaching it by 0.5 length of dactyl. 

 Second pereopod exceeding antennular peduncle 

 by length of propodus or by latter and 0.15 that of 

 carpus. Third pereopod overreaching antennular 

 peduncle by propodus and about 0.5 length of 

 carpus. Fourth pereopod surpassing antennular 

 peduncle by dactyl, propodus, and almost entire 

 length of carpus. Fifth pereopod exceeding anten- 

 nular peduncle by length of distal three podo- 

 meres. Pereopods increasing in length from first 

 to fifth. First pereopod with rather inconspicuous 

 spine on basis, and long slender spine on ischium; 

 second pereopod with minute spine on basis. In 



female, coxa of third pereopod produced into large 

 plate disposed at right angle to podomere, its 

 anteromesial margin bearing blunt, strong tooth. 

 Coxa of fourth pereopod produced in short, prom- 

 inent plate armed with numerous strong setae. In 

 both sexes, tooth present on anteromesial angle of 

 coxa of fifth pereopod, tooth considerably stronger 

 in males than in females, in latter minute and 

 borne on rounded coxal plate. 



Abdomen with middorsal keel from fourth 

 through sixth somites, and strong longitudinal 

 rib along lateral surface of fourth and fifth so- 

 mites; posterodorsal margin of latter somites with 

 shallow median incision; sixth somite very elon- 

 gate, 2.25 times as long as high, bearing small 

 sharp spine at posterior end of keel and pair of 

 minute posteroventral spines. Telson with broad 

 median sulcus, deep anteriorly, quite shallow 

 posteriorly, and flanked by low sharp ridges; ter- 

 minal portion length about 5 times basal width; 

 lateral spines short, their length 1.5-1.6 times 

 basal width of terminal portion of telson; mesial 

 ramus of uropod falling short, or slightly over- 

 reaching, apex of telson; lateral ramus exceeding 

 mesial ramus by 0.15-0.20 of its own length, and 

 armed with acute, terminal, distolateral spine. 



FIGURE 22.— Hymenopenaeus nereus, syntype cJ 15.5 mm cl, northwest of Punta Galera, Ecuador. A, Petasma (partly bent laterally), 

 dorsal view of right half. B, Ventrolateral view. C, Right appendices masculina and interna, dorsal view. D, Ventromesial view. 



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