I 9 I 5-] Fauna of the Chilka Lake : Crustacea Decapoda. 303 



The original specimens examined by Fabricius were from the " Indian Ocean " ; 

 Henderson' s material was obtained at Pulicat, a locality not far distant from Ennur. 

 Ortmann' s var. dolichognathus is recorded from the Bay of Tokyo and de Man' s var. 

 leptopus from the East Indian Archipelago, S. of Celebes. One specimen of the var. 

 leptopus was found at the unusual depth of 289 metres. 



Alpheus paludicola, sp. nov. 

 (Plate XIII, figs. 11-13.) 



A species belonging to the edwardsi group, allied to A. euphrosyne, de Man, and 

 A. microrhynchus , de Man. 



The rostrum is exceedingly small, less conspicuous even than in A. microrhynchus, 

 and consists of a minute triangular plate which reaches but little beyond the level of 

 the extremities of the orbital hoods. Behind it the inter-orbital region is flattened 

 and the post-rostral keel is quite obsolete, existing merely as an extremely feeble 

 elevation, which can only be seen in dried specimens and disappears altogether before 

 reaching the middle of the inter-corneal area. There are no perceptible inter-orbital 

 grooves on either side of the middle line. The orbital hoods are well in advance of 

 the anterior margin of the carapace on either side ; their frontal edges are not strongly 

 convex (pi. xiii, fig. 11). The carapace, except for a few microscopic punctuations, 

 is smooth. 



The lateral process of the basal antennular segment is broadly oval and termin- 

 ates in a small spine which does not reach the end of the segment. The second 

 segment is about equal in length with the first and about two and a half times as 

 long as broad ; the third segment is much shorter. The thickened portion of the outer 

 flagellum is a little longer than the peduncle. 



There is no anterior spine on the lower margin of the basicerite of the antenna. 

 The carpocerite is slender and reaches beyond the antennular peduncle by a distance 

 nearly equal to that of the last segment of the latter. The antennal scale (text-fig. 

 33a) is not so broad as in A. euphrosyne; the length is about 24 times the width. 

 The spine which terminates the slightly concave outer margin reaches very little, if 

 at all, beyond the apex of the lamella. 



The ultimate segment of the outer maxillipede is fully one and three quarters 

 the length of the penultimate ; both these segments are much more slender than the 

 antepenultimate . 



In the large chelipedes the merus in large males may be only twice as long as 

 broad; in a younger male 2*4 times and in an adult female 27 times. The upper 

 edge is rounded and the spine found in A . edwardsi and A . crassimanus at the distal 

 end of the infero-internal margin is absent. The carpus is very short, rounded above. 



The large chela (pi. xiii, figs. 12, 13) is from 2-4 to 2"5 times as long as broad, 

 the palm being about 1*5 times as long as broad. The rounded upper edge of the 

 palm terminates obtusely in front of a well-defined transverse groove situated near the 

 base of the dactylus; the lower edge ends more abruptly in a rounded prominence 



