1896.] A. Alcock — Carcinolofjical Fauna of India. 149 



Marsia, Milno-Edwards, Hist. Nat. Crust. II. 109. 

 Mursia, De Haan, Faun. Japon. Crust, p. 68 and p. 125. 

 Mrorsia, Miers, Challenger Brachynra, p. 290, (tthi synon.). 

 Thealia, Lucas, Ann. Soc. Entomol. France (1) VIII. 1839, p. 577. 



Carapace oval, moderately convex, rounded in front, rather sud- 

 denly contracted behind, the evenly -arched' antero-Iateral margins end- 

 ing in a large lateral epibranchial spine. 



Front with a small acuminate tip. 



Orbits rather large, oval, M^ith at least one closed but distinct 

 fissure in the upper margin, and with two wide gaps in the lower margin, 

 in one of which the basal joint of the antenna is lodged. Eyes large, 

 eyestalks short and thick. 



The antennules fold obliquely. The basal joint of the antennae is 

 not dilated. 



There is no distinct epistome, but, as in Calappa, the endostome is 

 prolonged into a canal, which however is but incompletely divided 

 longitudinally, the septum being little more than a ridge anteriorly, 

 though well developed posteriorly. As in Calappa the first pair of 

 maxillipeds give off each a lamellar process to complete this efferent 

 canal below. 



The external maxillipeds do not meet across the mouth, but, as in 

 Calappa, leave exposed between them the mandibles, and, in front, the 

 plate like prolongations of the first maxillipeds. 



The chelipeds are enlarged, much as in Calappa ; but the meropod- 

 ite, or " arm," instead of a transverse crest near the distal end of its 

 outer surface, has merely a ridge with one or two spines : the palm 

 is compressed and its upper border forms a dentate crest, but not such 

 a high one as that of Calappa. As in Galappa the chelipeds are only 

 asymmetrical as regards the fingers, which on one hand have on their 

 outer aspect, near the base, a stout lobule.* The legs are large, the 

 first two pairs being at least as long as the chelipeds. 



The abdomen in the male is as broad in the proximal half as it is 

 in the female : in the adult male it consists of five segments, the 3rd, 

 4th and 5th being intimately fused, the sutures even being hardly 

 distinguishable : in both sexes the tergum of the Jst somite is almost 

 entirely concealed, and that of the 2nd somite strongly carinate trans- 

 versely. 



Mursia is practically Galappa without the wings to the carapace, 

 and with large strong legs : the widely fissured orbital floor, the less 



* In Mursia haivaiiensis, Mary J. Rathbun, Proc. United States National 

 Museum, xvi. 1893, p. 252, the chelipeds are described as very unequal. 



