FISHERY BULLETIN: VOL. 83, NO. 1 



dorsally directed salient as it is in S. picta. Fur- 

 thermore, the distal projection of the ventrolateral 

 lobule in S. disdorsalis is laminar, bifurcate later- 

 ally, and bears a proximal plate bordered by a 

 transverse rib; in S. picta, it is roughly sickle 

 shaped in outline, tapering laterally to a sharp 

 proximoventrally directed apex. Finally, the 

 thelycal plate of sternite XIV in S. disdorsalis is 

 raised in a low but well-defined pair of lateral 

 protuberances instead of being flat or slightly 

 raised laterally as it is in S. picta. 



In the field, S. picta may be distinguished from 

 its sympatric congeners by the striking yellow 

 ocellus with a red center located on the bran- 

 chiostegite. 



Burkenroad (1938) discussed in detail the fea- 

 tures that distinguish S. picta from the western 

 Atlantic S. stimpsoni Bouvier 1905. Actually, fea- 

 tures cited by him for S. stimpsoni also apply to S. 

 burkenroadi, another western Atlantic species 

 which was not recognized until described by Cobb 

 in 1971. S icy onia picta differs from S. stimpsoni, 

 but resembles S. burkenroadi, in bearing strongly 

 curved spines on the anteroventral angles of the 

 second through fourth abdominal pleura. It, in 

 turn, can be separated from .S. burkenroadi, but 

 resembles S. stimpsoni, in lacking a posterior 

 tooth on the tergal carina of the fourth abdominal 

 somite. 



Remarks. — Arana Espina and Mendez G. (1978) 

 presented an illustration (Fig. 11) in which the 

 posterior tergal and posteromedian sulci of the 

 second and third abdominal somites appear co- 

 alescent. The disposition of the posteromedian sul- 

 cus seems to be in error because, as stated above, 

 the two sulci in this shrimp do not merge; instead 

 the posteromedian one extends anterodorsally, 

 ventral to the posterior tergal sulcus. 



In addition to citing many new localities, this 

 paper contains the first records of the species from 

 the ocean side of Baja California Sur, Mexico, as 

 far north as Bahia Magdalena. 



Material.— 602 specimens from 61 lots. 



Mexico — Baja California Sur: 19, AHF, 5.5 km 

 W of mouth of Bahia Magdalena, 64 m, 8 March 

 1949, Velero IV. U, USNM, off Isla Santa Mar- 

 garita, 86 m, 8 April 1889, Albatross stn 

 3039. 16 29, SIO, off Punta Marquez, 64 m, 9 

 November 1964. 29, SIO, Bahia de la Paz, 82-119 

 m, 12 January 1968, Thomas Washington . 26 69 , 

 SIO, Bahia de la Paz, 119-128 m, 24 July 1965, R. 

 Rosenblatt. 1<5, AHF, entrance to Bahia Agua 



62 



Verde, 42-48 m, 17 March 1949, Velero IV. 66 119, 

 SIO, NW of Isla Monserrate, 170-192 m, 11 July 

 1965, Horizon. 29, AHF, NW of Isla Danzante 

 Primero, 44-73 m, 18 March 1949, Velero IV. 16 , 

 YPM, Bahia de Santa Ines, 101 m, 17 March 1926, 

 Pawnee. 49, SIO, off Santa Rosalia, 35-26 m, 25 

 March 1960, R. Parker Baja California Norte 

 (all in Gulf of California): 19, YPM, Bahia de los 

 Angeles, 31-42 m, 13 May 1926, Pawnee. 3d 19, 

 AHF, Puerto Refugio, Isla Angel de la Guarda, 

 143-165 m, 28 January 1940. 39 , AHF, N of Isla 

 Angel de la Guarda, 104 m, 28 January 1940. 66 

 119, SIO, SE of San Felipe, 75-86 m, 19 January 

 1968, Washington. 16, YPM, Bahia San Luis 

 Gonzaga, 17 May 1916, Pawnee. 16 19, USNM, 

 off Punta San Fermin, 55 m, 27 March 1889, Alba- 

 tross stn 3035. 19 , SIO, SE of San Felipe, 120 m, 

 19 January 1968, Washington. Sonora: 26 

 29, USNM, off Cabo Tepoca, 65 m, 24 March 1889, 

 Albatross stn 3018. 266 299, USNM, SW of Cabo 

 de Lobos, 139 m, 24 March 1889, Albatross stn 

 3016. 16 , USNM, NW of Isla Tiburon, 265 m, 24 

 March 1889, Albatross stn 3015. 4(5 19, AHF, 3 

 km W of Tastiota, 60 m, 21 December 1978, A. 

 Kerotitch. Sinaloa: 3d 29 , USNM, off Punta 

 Santo Domingo, 135 m, 10 April 1889, Albatross 

 stn 3043. 19 , USNM, off Peninsula de Quevedo, 

 67 m, 30 March 1978, Toral Garcia. Nayarit: 



26 49, SIO, NE of Isla Maria Madre, Islas Tres 

 Marias, 82-88 m, 30 March 1973, Agassiz. 



Guatemala— 19, SIO, Champerico, 91-104 m, 13 

 April 1973, Agassiz. 



Nicaragua— 29, SIO, off N of Nicaragua, 53-59 

 m, 17 April 1973, C. Hubbs and S. Luke. 



Costa Rica— Id 19 , USNM, Golfo del Papagallo, 

 2 April 1978, D. Hedgecock. Id, SIO, Punta 

 Guiones, 104 m, 19 April 1973, C. Hubbs and S. 

 Luke. 1505 1509 , SIO, Golfo de Nicoya, 86 m, 22 

 April 1973, A^ass/e. 6d 19, SIO, off Cabo Blanco, 

 60 m, 18 April 1973, Agassiz. 19, UCR, off Cabo 

 Blanco, 249 m, 28 April 1973, Enriqueta. 16 149, 

 SIO, off Cabo Blanco, 137-144 m, 19 April 1973, C. 

 Hubbs and S. Luke. 19 , USNM, off Cabo Blanco, 

 247 m, 27 April 1973, Enriqueta. 



Panama— Id 19, AHF, Islas Secas, 46-48 m, 27 

 March 1939. 2d 69 , AHF, off Isla Medidor, 55-64 

 m, 28 March 1939, Velero III. 26 89, UR 25 km 

 S of Isla Cebaco, 256 m, 8 August 1972, 

 Canopus. 16, syntype, USNM, off Punta 

 Mariato, 333 m, 23 February 1891, Albatross stn 

 3355. Id 19 , USNM, E of Isla Iguana, 79-77 m, 2 

 May 1967, Pillsbury stn 502. 39, USNM, NE of 

 Isla Iguana, 79-77 m, 4 May 1967, Pillsbury stn 

 515. 4d 29, MCZ, and 2d 29, USNM, syntypes. 



