Synojjsis of the American Sesarmse. 91 



L'. Margins of iiieri of ambulator)^ legs converging 



from the middle towards the carpal joints. 



M. Front deeply concave ; protogastric lol)es 



strongly projecting. (iiKjK.std- .Smith. 



M'. Front slightly concave ; protogastric lobes 



slighth* projecting. 



(Dtgiisiipes Dana = amencami * Sanssure. 

 D'. Protogastric or supra-frontal lobes smooth or nearly so. 

 E. Front less than 4 times as wide as high. 



rlcordl* 3Iilue Edwards = guerini* Milne Edwards = min- 

 iata* S-Aussure := cDtgusllpes Stimpson (in part,* at least) 

 ^ angusiipes Smith* = stimpsonii Miers,* 1881, not 1S8G, 

 = clnerea Heilprin,* 1888, ^ clnerea Ives,* 1891. 

 E'. Front more than 4 times as wide as high. 



haiiseni Rathbun, new sjiecies. 



Sesarma (Holometopus) miersii Rathbun, new name. 



Sesarmn ongustipes f Miers, Proc. Zool. Soc. London, 1881, 70, Rat Island, 



]\lonte Video. 

 Ses(n-iaa ■^(impsaitii Miers, Challenger Rept, Zool., XVII, 270, 1880; not 



.S'. stimpsonii Miers, 1881. 



Carapace broader than long, of equal width anterioily and posteriorly, 

 surface more convex than in .S'. cjnerea, regions deeply marked. Carapace, 

 as in .S. roherti, punctate, the punctje crowded in places and tending to 

 coalesce ; anterior portion rougli with tubercles. Except for its width, the 

 carapace has great resemblance to that of S. roberii. 



Front less than four times as wide as high. Superior lobes less promi- 

 nent than in S. roberii. The middle sinus of the lower margin when 

 viewed from above is much shallower and less rounding than in that 

 species. Viewed from in front the lower margin forms an almost un- 

 broken convex line. The side margins of the front diverge below as in 

 >S'. riconU. 



The lateral margins of the third abdominal segment of the male are 

 arcuate, the abdomen being widest posterior to the distal end of that seg- 

 ment. The terminal segment is as wide as it is long. The appendages 

 terminate in an oblique sinuous margin fringed with hair. 



The chelipeds resemble pretty closeh' those of S. roberii. The meri of 

 the ambulatory legs are shorter than in that species, being less than 2h 

 times as long as wide in the first, third, and fourth pairs, and a little more 

 than 2h times the width in the second pair. Propodi of first and second 

 pairs hairy above and below : those of the third and fourth pairs hairy 

 only on the distal portion. 



Di)iiensions.—rJ, Abaco, Bahamas, U. S. Nat. Mus., Xo. 11372 : Length, 

 19.3 mm.; width, anteriorand posterior, 21.1 ; superior frontal width, 11 ; 

 inferior, 11.6; depth of front, 3; length of merus of third ambulator}' 

 leg, 15.3 ; width of same, 0.3. In some specimens the posterior width is 



*Type examined by the writer. 



