P6REZ FARFANTE: ROCK SHRIMP GENUS SICYONIA 



Rostrum 

 Dorsal tooth\ 

 Apical teethv 

 Adrostral carina- 

 Orbital margin- 

 Antennal spine- 

 Hepatic spine 



Pterygostomian 

 region 



Dorsum 



/Epigastric tooth 



Postrostral carina 



Branchiostegite 



Figure 2. — Lateral view of carapace oi Sicyonia showing terms used in descriptions. 



Figure 3. — Sicyonia disedwardsi Stimpson, 2 30 mm cl, Golfo 

 de Panama, Panama. Eye, dorsal view: b, basal article; c, 

 cornea; o, optic calathus; p, ocular plate; s, ocular stylet. Scale 

 = 1 mm. 



trapezoidal; first maxilla (Fig. 4S) with broad palp 

 unjointed and not produced distally; second 

 maxilla (Fig. 4C) with basipodite lacking proxi- 

 mal gnathal lobule; first maxilliped with flagel- 

 lum quite short (Fig. 4D); second maxilliped as 

 illustrated (Fig. 4E). Exopods lacking on second 

 and third maxillipeds and all pereopods. First 

 pereopod unarmed or with mesial spine on basis 

 and ischium. Endopods of pleopods absent except 

 for highly modified ones on first (petasma) and 

 second (bearing appendix masculina) pleopods. 

 Petasma (Fig. 5A) depressed, with dorsolateral 



and heavily cornified ventrolateral lobules pro- 

 duced in distal projections, that of former funnel- 

 like, and with ventromesial slit; distal part of 

 dorsomedian lobule bearing short distal plate 

 resembling cusp in ventral aspect. Appendix mas- 

 culina (Fig. 5B ) projecting from free distal part of 

 ridge on dorsomedian margin of endopod, small, 

 roughly bellshaped, but with membranous termi- 

 nal wall. Male gonopores situated on sternite XIV. 

 Thelycum (Fig. 6) with plate of sternite XIV 

 single, flat or raised in paired, weak or prominent, 

 lateral bulges. Paired seminal receptacles (Fig. 7) 



