NO. 9 manning: Atlantic stomatopod Crustacea 15 



present ; mandibular palp absent ; lateral process of fifth thoracic 

 somite a sharp spine directed laterally, straight or slightly curved or an 

 obtuse lobe, directed obliquely forward ; lateral processes of sixth and 

 seventh thoracic somites faintly emarginate anteriorly, rounded pos- 

 teriorly; submedian carinae present only on sixth abdominal somite; 

 other abdominal carin£e sharp, prominent, spined as follows: submed- 

 ian, 6; intermediate, 5-6; lateral, 5-6; marginal, (4)-5; telson with 

 sharp crest ending in a posterior spine; only submedian spines of tel- 

 son carinate, the carinae extending forward to base of terminal spine 

 of crest ; submedian spines with movable tips ; prelateral lobes absent ; 

 denticles 4-6, 8-9, 1 ; uropodal outer branch with 5 graded, movable 

 spines on outer margin, the last extending to midpoint of ultimate seg- 

 ment; basal prolongation of uropods with 2-6, usually 3-4, immovable 

 spines on inner margin of inner spine. 



Discussion: This small species is closely related to S. schmitti Lemos 

 de Castro and S. tricarinata Holthuis from which it differs in having 

 short submedian carinae on the telson. S. polita Bigelow is the Eastern 

 Pacific analogue of S. quadridens. 



Remarks: The present material extends the range of this species in 

 northern South America from Suriname to British Guiana and Colom- 

 bia. 



The male from OREGON Sta. 2249 has the margins of the telson 

 and the carinae of the sixth abdominal somite noticeably swollen; 

 this is probably a sexual character. 



The shape of the lateral process of the fifth thoracic somite varies 

 in the present material. In the type, from Florida, and the OREGON 

 specimen, the process, in anterior view, is a thin, elongate, sharp spine. 

 In the Colombia material, the process, in anterior view, is rounded, not 

 acute laterally. The difference may be a specific character, but the ma- 

 terial from the two locations shows no other important differences. 



The color of this species is as follows: a broad transverse band of 

 dark color extends across the posterior fourth of the carapace; there is 

 a rectangular patch of dark color on the dorsum of the second abdom- 

 inal somite; a short line of dark color is found on the last three 

 thoracic and each abdominal somite at the intermediate carinae, and 

 the line on the sixth abdominal somite is longer than on the anterior 

 ones; there is a dark spot at each end of the median carina of telson; 

 the inner branch and the distal segment of the outer branch of the 

 uropods are lined with dark chromatophores. 



