FISHERY BULLETIN; VOL. 83, NO. 1 



ing in height from low anterior part (between 

 epigastric and middle teeth) to posterior tooth, 

 descending gradually from it to posterior margin 

 of carapace. Antennal spine relatively long, sharp, 

 and projecting from short buttress; hepatic spine 

 acutely pointed, arising from moderately raised 

 area, and placed between 0.19 and 0.26 (mean 0.22) 

 cl from orbital margin. Postocular sulcus short but 

 deep, continuing posteriorly as barely distinct 

 narrow groove; hepatic sulcus shallow; bran- 

 chiocardiac carina broad, long, extending lon- 

 gitudinally from hepatic region almost to posterior 

 margin of carapace where bifurcate: one branch 

 curving dorsally and other, short, disposed 

 ventrally. 



Eye as illustrated in Figure 3. Ocular stylet 

 with terminal part often bent laterally in young, 

 but usually straight in larger individuals. 



Antennular peduncle with stylocerite produced 

 in long spine, its length 0.80 to 0.90 distance be- 

 tween lateral base of first antennular article and 

 mesial base of distolateral spine; latter extending 

 as far as distal 0.3 of second antennular article; 

 antennular flagella short, maximum length 0.25- 

 0.35 cl, mesial flagellum slightly shorter than lat- 

 eral in young but subequal to or slightly longer in 

 larger adults. 



Scaphocerite nearly or quite overreaching an- 

 tennular peduncle by as much as 0.15 its own 

 length; lateral rib ending distally in long, acute 



spine conspicuously surpassing margin of lamella. 

 Antennal flagellum as much as 2.2 times as long 

 as carapace. 



Third maxilliped stouter than pereopods. Basis 

 and ischium of first pereopod unarmed. 



Abdomen with high dorsomedian carina ex- 

 tending from first through sixth somites, carina on 

 first produced in strong tooth, sometimes disposed 

 almost horizontally, but usually elevated as much 

 as 55°, tooth tapering to sharp apex, and consider- 

 ably larger than posterior one on carapace; carina 

 on fifth somite produced in small tooth and that on 

 sixth terminating in strong sharp one. 



Anterior margin of pleuron of first abdominal 

 somite straight or very slightly concave; antero- 

 ventral extremity of pleuron of first through 

 fourth somites ending in spine, that of first usually 

 directed anteroventrally, spines on second through 

 fourth often curved posterolaterally; posteroven- 

 tral margin of first through third somites rounded, 

 that of fourth broadly angular, sometimes bearing 

 node or minute spine, and that of fifth and sixth 

 sharply angular and armed with small, caudally 

 directed spine. Pleural spination of first four so- 

 mites barely if at all distinct in juveniles, becom- 

 ing stronger with increasing length of carapace. 



First somite traversed by deep, long anterome- 

 dian pleural sulcus (sometimes obsolete along 

 midlength), latter usually converging with united 

 posterior tergal-posteromedian pleural sulci ven- 



FlGURE 28. — Sicyonia disedwardsi , S 23.5 mm cl, Golfo de Panama, Panama. A, Petasma, dorsal view; 

 B, ventral view of same; C, right appendix masculina, dorsolateral view. Scale = 1 mm. 



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