SOUTHWELL ANOMURA 1 1 3 



Seven specimens, one male and six females, five of the latter bearing eggs, 

 and one being a young specimen. 



Locality: Challai Paar, Gulf of Mannar, four and a half fathoms; bottom, 

 sand. Found commensal on a species of Spongodes, having dark purple tips. 



This species bears a general resemblance to PorceUana serratifrons, but differs 

 from it very definitely in the following particulars : 



(1) The median lobe of the rostrum is slightly concave instead of rounded. 



(2) The propodite of the chelipede is smooth. 



(3) The dactyli of the thoracic feet are multiunguiculate. 



This species appears to be related to PorceUana, nitida, Haswell, but his 

 description is so short and incomplete that it is inconclusive. 



The median rostral lobe of P. nitida is said to be " much longer than the 

 other," without any further description. Moreover, PorceUana gaekwari, n. sp., 

 has the rostrum spinose. The carpus of the chelipede in P. nitida has a sharp entire 

 internal crest. Only the males of P. gaekwari, n. sp., have the carpal crest entire. 



This species is variable. The young specimen had the chelipedes only one and 

 a half times as long as the carapace, and equal. la others, the chelipedes were 

 sometimes equal, or the left or right was slightly the larger. 



The spines on the internal edge of the carpus of the chelipedes of the female 

 were variable in number, as shown in the following table : 



Specimen. Carpun of R. Chelipede. Carpux oj L. Chelipede. 



1 3 spines 2 spines and many minute ones distally. 



2 4 ,, 5 spines. 



3 4 * 



4 8 5 



5 7 5 



6 3 4 



This species undoubtedly belongs to the genus PorceUana, as defined in the 

 Report on Challenger Anomura. 



A noticeable feature was, that in the fresh condition the eyes were non-pigmented, 

 the pigment only developing after death, and even then not being very pronounced. 

 Amongst the characteristics of this genus is the fact that the dactyli of the ambulatory 

 limbs terminate in a single claw, and also that the first joint of the antennal peduncle 

 is joined to the margin of the carapace. 



PorceUana gaekwari, n. sp., differs markedly in both these particulars. How- 

 ever, its general characteristics are more those of a PorceUana than of any other 

 genus, and it is accordingly placed here. 



This species is named in honour of H.H. the Maharaja Gaekwar of Baroda, to 

 whose liberality is due the carrying through of the investigation of which the present 

 report forms part. 



