Subfamily Sesarminae 



Front strongly deflexed. Lower border of orbit 

 commonly running: downward toward angle of 

 buccal cavern. Side walls of carapace finely re- 

 ticulated with granules and hairs or hairs only. 

 External maxillipeds separated by a wide rhom- 

 boidal gap, an oblique hairy crest traversing them 

 from a point near anteroexternal angle of ischium 

 to a point near anterointernal angle of merus; 

 palp articulating either at summit or near antero- 

 external angle of merus; exognath slender and 

 either partly or almost entirely concealed. Male 

 abdomen either filling or not quite filling all space 

 between last pair of legs (Rathbun, 1918b). 



Genus Sesarma Say, 1817 



Rathbun, 1918b, p. 284. 



KEY TO SPECIES IN THE CAROLINAS 



a. Lateral margin of carapace sinuous ; last three articles 

 of first three walking legs tomentose ; body strongly 

 convex above reticulatum (p. 221). 



aa. Lateral margin of carapace straight ; walking legs not 

 tomentose; body nearly flat above c'mercum (p. 222). 



Sesarma (Sesarma) reticulatum (Say) 



Figure 205 



Ocypode reticulatus Say, 1817, p. 73, pi. 4, fig. 6. 

 Sesarma reticulatum: Rathbun, 1918b, p. 290. pi. 77 (rev.). 

 Sesarma reticulata: Hay and Shore. 191S. p. 448, pi. 36, fig. 12 

 (rev.). 



Recognition characters. — Carapace about four- 

 fifths as long as broad, convex, regions distinct, 

 surface punctate and with scattered clumps of 

 setae above and in front ; sides concave behind 

 widest point, convergent at orbital angles. Pos- 

 terolateral regions obliquely striated and setose; 

 inferolateral and frontal regions with irregular 



Figure 205. — Sesarma (Sesarma) reticulatum (Say). 

 Animal in dorsal view, 10 mm. indicated. 



rows of tubercles bearing short, curved hairs. Dor- 

 sal portion of carapace overhanging sides; be- 

 neath projecting shelf a line of cilia. Lower sur- 

 face of carapace covered with fine net of geniculate 

 hairs. Front broad, slightly sinuate above basal 

 articles of antennae. Eyestalks short and stout, 

 set in deep oval orbits; a deep gap below outer 

 orbital angle leading into system of grooves open- 

 ing into a notch at anterolateral angle of buccal 

 cavern. External maxillipeds separated by a wide 

 rhomboidal gap largely filled by a hairy fringe, 

 and obliquely traversed by a conspicuous line of 

 hairs from point behind anteroexternal angle of 

 ischium to anterointernal angle of merus. 



Chelipeds stout, subequal in male; merus and 

 carpus lightly rugose; merus with an obtuse sub- 

 terminal tooth above, both lower margins denticu- 

 late; carpus with inner angle rounded. Palm al- 

 most smooth, in male a little higher than 

 midlength, upper edge with a single granulate 

 line, inner surface with a short irregular ridge of 

 tubercles near distal end; dactyl with seven to 

 nine depressed spinules above on basal two-thirds ; 

 fingers agape, an enlarged tooth near each end. 

 Palm of female half again as high as midlength, 

 fingers slightly agape. Third pair of walking legs 

 approximately twice as long as carapace, last 

 three articles densely tomentose. 



Measurements. — Carapace: male, length, 23 

 mm. ; width, 28 mm. 



Color. — Carapace, dark olive, nearly black or 

 purple ; dark plum colored or bluish-black speck- 

 les crowded on grayish background, grayish color 

 showing little except on posterior part ; upper 

 part of chelipeds similarly colored but brighter, 

 greater part of palm yellowish, tips of fingers 

 white or yellowish; upper part of legs as cara- 

 pace; under parts grayish (various authors). 



Habitat. — Burrows in muddy salt marshes. 



Type locality. — Muddy salt marshes [east coast 

 of United States] . 



Known range. — Woods Hole, Mass., to Calhoun 

 County, Tex. 



Remarks. — Ovigerous females have been re- 

 ported from Massachusetts in July, and in sum- 

 mer months farther south on the coast. Crichton 

 (1960) found 8,000 to 10,000 eggs per egg mass. 



Hyman (1924b) described the first zoeal stage 

 and compared it with S. ckiereum. Recently, Cost- 

 low and Bookhout (1962a) described the complete 



MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS 



221 



