KRYGIER and WASMER: NEW NORTHEASTERN PACIFIC PELAGIC PENAEID SHRIMP 



dorsal spine; carina absent between well-defined 

 cervical and postercervical sulci and on posterior- 

 most portion of the carapace. Mid-lateral longi- 

 tudinal carina consisting of strong antennal 

 carina continuous with hepatic and branchial 

 carinae. Branchiostegal spine small and 

 branchiostegal carina distinct; hepatic sulci con- 

 tinuous from branchiostegal spine towards lower 

 margin of carapace; post-hepatic carina orientated 

 dorsoventrally from longitudinal hepatic carina 

 toward inferior margin of carapace. Antennal 

 angle obtuse and infra-antennal angle acute 

 (Figure 2a). 



Only sixth abdominal somite with middorsal 

 carina; second through fifth abdominal somites 

 with weak lateral ridges in approximately dor- 

 soventral position extending from mid-lateral to 

 ventrolateral edge of the pleuron. Fourth, fifth, 

 and sixth abdominal somites with prominent, 

 roughly transversal, lateral ridges which together 

 form "half moon" area (Figure 1). Fourth and fifth 

 abdominal somites bearing small mid-lateral tooth 

 on posterior margins. 



Antennal flagellum (Figure 1) similar to Gen- 

 nadas (Foxton 1969), having proximal and distal 

 sections divided by short series of annuli forming 

 kink in flagellum; proximal section rigid, bearing 

 scattered short nonplumose setae; distal section 

 bearing paired arched plumose setae with small 

 plumose setae perpendicular to flagellum at 

 irregular intervals between bases of some arched 

 pairs. Second element of antennular peduncle, 

 along dorsal midline, 0.7 ultimate element (Figure 

 2b). Antennal scale (Figure 2c) little less than 3 

 times as long as greatest width; distinct spine 

 (outer margin of scale), slightly convex, terminal 

 end free, not extending beyond narrow apex of 

 blade. 



Mandible (Figure 2d) with two segmented palp; 

 palp thickly covered with setae on medial and 

 lateral margins, distal element not quite as long as 

 widest portion of basal element. Endopod of first 

 maxilla (Figure 2e) distally narrow, with tip 

 rounded; proximal gnathobasic lacinia (endite of 

 coxa) subequal in width to distal lacinia (endite of 

 basis), both terminating in strong spines among 

 setae fringe. Anterior lobe of proximal lacinia 

 (endite of coxa) of second maxilla (Figure 2f) 

 strongly constricted behind apex, not broader than 

 posterior lobe of distal lacinia (endite of basis); 

 anterior lobe of distal lacinia very broad; endopod 

 distally long and narrow, with two (sometimes 

 three) curved spines at base of apical portion. 



Endopod of first maxilliped (Figure 2g) reaching 

 beyond endite of basis but falling short of exopod; 

 endopod of four elements, third less than twice 

 second; fourth extremely minute; first element 

 bearing usual compliment of three curved spines 

 on distomesial margin. Exopod bladelike, without 

 constricted, segmented distal portion. Merus of 

 second maxilliped (Figure 2h), including anterior 

 prolongation, 1.9 times as long as wide; dactylus 

 with single strong apical spine surrounded by 

 medium and small spines back to proximal end of 

 propodus; merus and carpus with numerous spines 

 and setae; podobranch present. Third maxilliped 

 (Figure 2i) reaching to, or beyond, middle of ul- 

 timate joint of antennal peduncle; ischium nearly 

 3 times as long as greatest width; merus usually 

 twice as long as greatest width; carpus slightly 

 longer than propodus; dactylus with long slender 

 terminal spine; podobranch present. 



Merus of first pereiopod (Figure 3a) 1.4 times 

 length of carpus and 1.7 ischium; fingers slightly 

 setose. In second pereiopod (Figure 3b), carpus 1.2 

 times length of propodus; merus 1.2 carpus and 1.5 

 propodus; chela with heavy tufts of bristles. Merus 

 and carpus of third pereiopod (Figure 3c) of equal 

 length, each twice ischium; fingers of chela similar 

 to those of second pereiopod. Carpus and propodus 

 of fourth pereiopod nearly equal, each 

 approximating two-thirds of merus which is 2.4 

 times ischium. Propodus of fifth pereiopod 

 subequal to carpus which is subequal to merus; 

 ischium slightly more than one-third of merus. 



Outer scale of appendix masculina (Figure 3d) 

 longer than inner; proximal half of lateral margin 

 expanding slightly then tapering toward base. 

 Inner scale broadly rounded distally; spines on 

 distomesial margin (few to many) long and thin, 

 spines on distal margin smaller, stronger, and of 

 uniform length. 



Telson with single pair of mobile terminal- 

 lateral spines (Figure 3e) fringed with setae on 

 terminal and distal two-thirds of lateral margins 

 (of the large number of specimens inspected, only 

 two mature males had any indication of more than 

 one pair of mobile spines (USNM 150839, 150840), 

 each with two pair of mobile spines on terminal 

 edge of telson). No mobile nonterminal-lateral 

 spines present on telson. Lateral margins of 

 lateral rami of uropods (Figure 3f) bearing spine 

 at 0.78 total length. Mesial rami about 0.73 lateral 

 rami. 



Each half of petasma (Figure 3g, h), distally 

 divided into three lobes (external, median, and in- 



739 



