2o6 Records of the Indian Museum. [Vor,. XIII, 



are often found together. L. potamiscus has been found only 

 three times, on each occasion in water that was fresh but subject 

 at times to tidal influence: L. annandalei and L. modestus appear 

 to be inhabitants of pure fresh water. The most remarkable 

 species from the point of view of habitat is L. fluminicola , which 

 although occasionally taken in water of slight salinity, also occurs 

 in rivers far above tidal influence and has even been found at 

 Mirzapur in the United Provinces at a distance of fully 700 miles 

 by river from the coast. 



All the species here referred to the genus Leander possess a 

 mandibular palp of three segments. The maxillae and maxilli- 

 pedes are remarkably uniform in structure, differing little if at 

 all from those of L. serratus (Pennant). 



Leander tenuipes, Henderson. 

 (Plate viii, fig. i.) 



1893. Leander tenuipes, Henderson, Trans. Linn. Soc, Zool. (2), V, p. 440, 



pi. xl, figs. 14, 15. 

 1903. Leander tenuipes, Nobili, Boll. Mas. Torino, XVIII, no. 452, p. 7. 



The rostrum is variable in length, extending beyond the apex 

 of the antennal scale by a proportion varying from one fifth to 

 nearly one half of its length. The basal crest is well elevated and 

 bears from 5 to 7 teeth,' of which from 2 to 4 are situated on the 

 carapace behind the orbit. The teeth increase in size from behind 

 forwards, the hindmost being as a rule quite rudimentary. The 

 foremost tooth of the series does not reach the end of the first seg- 

 ment of the antennular peduncle. In front of the basal crest, 

 the rostrum trends downwards, but before reaching the end of the 

 antennular peduncle is reflected strongly upwards and is continued 

 almost in a straight line from this point to the apex. On the 

 dorsal edge near the tip there is, almost without exception, a single 

 tooth. The lower margin is provided with from 2 to 6 teeth, nearly 

 always 4 or 5 ^ ; the teeth are small and widely spaced and the 

 proximal one is well in advance of the foremost of those that con- 

 stitute the basal crest (pi. viii, fig. i). 



The antennal and branchiostegal spines are about equal in 

 length ; the latter is flanked by a short carina and is placed on the 

 extreme frontal margin of the carapace, not a little distance be- 

 hind it as in some other species of the genus. In the eyes the 

 breadth of the cornea is about equal to the length of the stalk ; 

 there is no visible ocellus. 



The spine forming the lateral process of the basal antennular 

 segment is very inconspicuous. The second peduncular segment, 

 measured dorsally, is exceedingly short, much less than half the 

 length of the third. The short ramus of the outer antennular 



' Of 42 specimens, eight have 5 teeth on the basal crest, twenty-one have 6 

 teeth and thirteen have 7 teeth. 



2 Of 42 specimens, two have 2 inferior teeth, three have 3 teeth, si.'cteen have 

 4 teeth, nineteen have 5 teeth and two ha\'e 6 teeth. 



