FISHERY BULLETIN: VOL. 83, NO. 1 



Figure 18. — Sicyonia mixta Burkenroad, 1946, 6 12 mm cl, off Cabo San Lucas, Baja California Sur, Mexico. Lateral 



view. Scale = 5 mm. 



one, but about twice as high as anterior, situated 

 posterior to hepatic spine, between 0.30 and 0.33 cl 

 from orbital margin; and 3) posterior tooth, be- 

 tween 0.60 and 0.63 cl. Tuft of setae present at 

 anterior base of each tooth. Antennal spine well 

 developed, projecting from short buttress; hepatic 

 spine long, sharp, borne on prominent buttress 

 arising from swollen hepatic region; branchiocar- 

 diac carina barely distinct, only for short distance 

 behind latter region. Postocular sulcus short and 

 deep anteriorly, continuing posteriorly as well- 

 defined groove; hepatic sulcus well marked, long, 

 extending caudally to about level of apex of pos- 

 terior tooth. 



Antennular peduncle with stylocerite produced 

 in long, acute spine, its length almost or quite 

 equal to distance between lateral base of first an- 

 tennular article and mesial base of distolateral 

 spine; latter sharp, long, reaching as far as distal 

 margin of second antennular article; flagella rela- 

 tively elongate, mesial one about 0.20 cl, shorter 

 than lateral, latter about 0.30 cl. 



Scaphocerite reaching or surpassing antennular 

 peduncle, sometimes by as much as 0.10 its own 

 length; lateral rib produced distally in long, sharp 

 spine overreaching lamella; antennal flagella in- 

 complete in all specimens examined. 



22 



Third maxilliped stouter than pereopods. Basis 

 and ischium of first pereopod unarmed. 



Abdomen with dorsomedian carina extending 

 from first through sixth somites, carina weak on 

 first and second, increasing progressively in 

 height through sixth; carina on first somite lack- 

 ing anterior tooth; on second interrupted by 

 well-marked depression limited posteriorly by 

 abrupt elevation, situated at level of juncture of 

 tergal sulci; on fifth descending gradually instead 

 of truncate posteriorly; and on sixth ending in 

 large, acute, posterior tooth. 



Pleuron of first abdominal somite with antero- 

 ventral margin slightly concave, anteroventral ex- 

 tremity rounded and unarmed; posteroventral ex- 

 tremity of first four somites also rounded, that of 

 fifth usually bearing minute spine, and that of 

 sixth always produced in small spine. 



First somite with very short but deep anterome- 

 dian pleural sulcus and relatively weak (similar to 

 most remaining sulci) but long posterior tergal 

 (extending 0.60-0.66 height of somite). Second and 

 third somites bearing short anterior and quite 

 long posterior tergal sulci. Fourth somite with 

 long posterior tergal sulcus, but anterior tergal 

 almost indistinct. Fifth somite with barely dis- 

 tinct anterior tergal and relatively short posterior 



