FISHERY BULLETIN: VOL. 83, NO. 1 



Figure 11. — Sicyonia laevigata. Thelyca. A,? 7 mm cl, Isla San Lucas, Costa Rica; B, J 9 mm cl, Punta Paitilla, Panama. Scales 



= 0.5 mm. 



slightly to conspicuously notched near midlength. 



Petasmal endopods coupled in males with 

 carapace length as little as 2.9 mm, about 13 mm 

 tl, petasma joined in all larger males. 



Appendix masculina as illustrated in Figure 

 IOC. 



Thelycum (Fig. ILA, B) with plate of sternite 

 XIV produced in elongate, subalate anterolateral 

 lobules, their anteromesial borders strongly di- 

 vergent; plate flat except for deep, broad, antero- 

 median depression, limited posteriorly by raised 

 margin of posterior thoracic ridge. Median plate of 

 sternite XIII narrow, lanceolate, tapering gently 

 into sharp spine reaching as far as midlength of 

 coxae of extended second pereopods; plate con- 

 stricted and excavate at level of fourth pereopods; 

 posterior component of plate with posterior mar- 

 gin entire to deeply emarginate and traversed by 

 weak suture. Paired conspicuous spines projecting 

 anteroventrally from posterior margin of sternite 

 XI. Posterior thoracic ridge insensibly fused later- 

 ally with plate of sternite XIV. 



The smallest impregnated female observed has 

 a carapace length of 5 mm, about 18 mm tl. 



Co/or.— Huff and Cobb (1979) presented a detailed 

 14 



account of the color pattern of this species based 

 on specimens collected on Florida's west central 

 shelf 



Maximum size. — Males 7.3 mm cl, about 34 mm tl; 

 females 15 mm cl, about 53 mm tl. 



Geographic and bathymetric ranges. — In the 

 American Pacific, S. laevigata is known from 

 Mazatlan (lat. 23°13'N, long. 106°25'W), Mexico 

 (Rodriguez de la Cruz 1977); Isla San Lucas 

 (9°56'N, 84°54'W), Golfo de Nicoya, Costa Rica; 

 and the Golfo de Panama, in the latter as far as 

 Punta Paitilla (8°58'N, 79°31'W), Panama. In the 

 western Atlantic this species ranges from off Cape 

 Hatteras (35°08'30"N, 75°10'00"W), N.C., south- 

 ward and into the Gulf of Mexico to northwest 

 Florida, and off Yucatan. Also, it occurs through 

 the Antilles and around the Caribbean coast of 

 Mexico, Central America, and South America, and 

 along the Atlantic coast of South America to Anse 

 de Zimbros (27°13'S, 48°31'W), Santa Catarina, 

 Brazil (Fig. 12). 



In the Pacific, this shrimp has been taken from 

 tide pools to a depth of 4-9 m, but in the Atlantic it 

 occurs from the shore to as deep as 90 m. It occurs 



