BRACHYURA. 



359 



grooves present; (4) the granules on the arm and hand are not so sharp; (5) the 

 strip of carapace cut off laterally by the skirting channel is narrower ; between the 

 slightly broadened portions which lie above the bases 

 of cheliped and walking legs 1 and 3 it forms a quite 

 thin ledge ; (f>) the sub-hepatic region is swollen, much 

 as in L. scidptus, and the small tubercle at point of 

 union of antero-lateral and postero-lateral borders is 

 not double. 



Remarks. The single specimen is immature, but its 

 order of size is much the same as that of a British 

 Museum specimen of L. sculpta. This species is of rare 

 occurrence. Only two other examples are known to me, 

 from two localities (Arafura Sea and Eastern seas), 



but closely resembling each other, suggesting that variability may be low. 

 present form may turn out to be the representative of a new species. 



Fig. 



Lithadia sculpta, var. 

 aglypha, now 



The 



Nursia plicata (Herbst), 1804, nee auctorum A. 2, p. 180. 



Localities : Adam's Bridge, one specimen (a) ; pearl banks, Gulf of Manaar, one 

 specimen (b). 



Description: 0.1. C.b.H-C.l. Oh.l.-5-C.l. F.l.-=-H.l. 



(a) adult S . . 10"25 127 T63 0"55 



(6) adult 6". . 12-50 1-20 172 0\54 



In carapace length the posterior point is the indentation between the two posterior 

 lobes. Carapace breadth measured by straight line uniting indentations between 

 2nd and 3rd lateral teeth of either side. In both specimens the greatest carapace 

 breadth is given by a straight line uniting tips of 2nd lateral teeth of carapace not 

 3rd pair as in N. hardwicki. 



Nursia hardwicki, Leach, 1817 A. 2, p. 181. 



Localities : Pearl banks, Gulf of Manaar, one specimen (a) ; Aripu Reef, one 

 specimen (b) ; coral reefs, Gulf of Manaar, one specimen (<). 

 Description (G.l. and C.b. measured as in N. plicata) : 



C.l. C.b.-C.l. Gh.l.H-C.l. F.1.-5-H.1. 



()$ . . . 10-25 1-15 1-51 0-61 



(&) . . . 10-75 1-12 1-49 0-56 



(()? . . . 11-00 I'll 1-50 0-55 



The most anterior of the four antero-lateral teeth, just behind the marginal nodule, 

 is quite conspicuous in (a), but only slightly developed in the other examples. In 

 all the greatest carapace breadth is given by a straight line uniting tips ot 3rd lateral 

 teeth not 2nd as in X. plicata. 



