PfeREZ FARFANTE: ROCK SHRIMP GENUS SICYONIA 



sially to apex. Thelycum with plate of sternite XIV 

 produced in elongate anterolateral lobules, their 

 anteromesial borders strongly divergent. 



Description. — Body moderately robust (Fig. 13) 

 and lacking tubercles. Carapace with short setae 

 scattered over surface and extremely long ones 

 between and flanking base of teeth on postrostral 

 carina. 



larger adults) flanking ventral margin of rostrum 

 posterior to apical teeth. Adrostral carina, sub- 

 parallel and distinctly dorsal to ventral margin, 

 extending almost to base of apical cluster 



Carapace with weak postrostral carina bearing 

 three subequal, acutely produced teeth: 1) 

 epigastric tooth, often larger than first rostral and 

 nearly as large as posterior teeth, situated be- 

 tween 0.12 and 0.25 (mean 0.17) cl from orbital 



Figure 13. — Skyonia disparri, holotype 9 10.4 mm cl, Bahia San Luis Gonzaga, Baja California Norte, Mexico. Lateral 



view. Scale = 5 mm. 



Rostrum long, reaching as far as distal margin 

 of second antennular article, its length (0.40-0.70 

 cl) increasing linearly with carapace length (Fig. 

 14); relatively deep, with dorsal and ventral mar- 

 gins subparallel; upturned to angle between 15° 

 and 45°; armed with three dorsal teeth and two 

 (7%), three (34%), four (57%), or five (2%) apical 

 teeth, additional rudimentary one present be- 

 tween two ventral ones; ventralmost tooth largest 

 of apical cluster, subterminal, directed anteriorly 

 or curved upward, and distinctly removed from 

 adjacent tooth. Position of first dorsal tooth rang- 

 ing from slightly posterior to level of orbital mar- 

 gin, to as much as 0.30 (mean 0.18) rl anterior to it; 

 that of second tooth between 0.40 and 0.65 (mean 

 0.50) rl from orbital margin, and that of third 

 between 0.65 and 0.90 (mean 0.75) rl. Paired mi- 

 nute, movable spinules (sometimes absent in 



3 6 9 12 



carapace length (mm) 



\5 



Figure 14. — Sicyonia disparri. Relationship between rostrum 

 length and carapace length (regression equation, y = -0.03809 

 + 0.51152X). 



17 



