I Cardiological Fauna of India. 215 



Hyastenus gracilirostris, Miers. 



Hyastenus gracilirostris, Miers, Ann. Mag. Nat. Hist., Vol. IV. 1879, p. 12, pi. iv. 

 fig. 7; and ' Challenger ' Brachyura, p. 56. 



Carapace subpyriform, hardly at all setose, with numerous sharp 

 tubercles and spinules. Specially noticeable are three spinules, longi- 

 tudinally arranged in the middle line, on the gastric region, a strong 

 conical spine on the cardiac region, a sharp tubercle on the posterior 

 margin, and two spines on each of the branchial regions, of which the 

 larger occupies the usual position of the lateral epibranchial spine. 



The rostrum, which does not vary according to sex, consists of two 

 slender divergent spines, the length of which is about one-third that of 

 the carapace. The post-ocular lobe projects very strongly, and the 

 supra-ocular eave has both the anterior and the posterior angle pro- 

 nounced. The basal antennal joint has a well-marked tubercle or blunt 

 spine at its antero-external angle. 



The chelipeds in the male are equal in length to the post-rostral 

 portion of the carapace, and have a few small granules on the merus 

 carpus and upper edge of the palm ; the merus is slender, but the 

 palm is broadened and is not much longer than the fingers, which are 

 arched and meet only at the tip. In the female the chelipeds are rather 

 shorter than the post-ocular portion of the carapace, are very slender, 

 and have nearly straight fingers. 



The ambulatory legs are slender, with slender smooth-edged dactyli : 

 the first pair are, as usual, much the longest. 



This also is a small- species, and egg-laden female of average size 

 being only 10 millim. in length. 



In the Museum collection are specimens from the Madras coast. 



Hyastenus tenuicornis, Pocock. 

 Hyastenus tenuicornis, Pocock, Ann. Mag. Nat. Hist., Vol. V. 1890, p. 76. 



Distinguished by the enormous length of the rostral spines, and by 

 the curious form — described below — of the supra-ocular eave and post- 

 ocular lobe. 



Carapace subpyriform, somewhat depressed, with the regions well- 

 defined ; its surface with many long scattered setae, and with numerous 

 granules and some large spines. Specially noticeable are five or seven 

 granules, arranged in the form of a cross, on the gastric region ; two 

 huge acuminate tubercles, in the middle line, posteriorly; and three 

 spines on either branchial region, the hindmost and lowermost of which 

 is of great size. 



The rostrum consists of two slender, exceedingly divergent spines, 



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