220 J. G. DE Man : The Fauna of Brackish Ponds. [Vol. II, 



and 5*5 mm. broad, appearing, in the latter, considerably broader 

 than in the male ; the following joints are also slenderer in the male. 

 The upper margin of the meropodites of the four ambulatory legs 

 is armed, in the female, with an acute tooth near the distal end and 

 this tooth is preceded, on the antepenultimate and penultimate 

 pairs, by nine or ten smaller teeth that gradually become smaller. 

 In the adult male the subdistal tooth is present on the meropodites 

 of the four legs, but it is comparatively smaller than in the female, 

 and the teeth that precede it, on the antepenultimate and penulti- 

 mate pairs, are quite rudimentary, hardly recognizable. The 

 ambulatory legs of the male are everywhere tomentose, in the 

 female the mero- and carpopodites are nearly glabrous. 



Geographical distribution : Ceylon (Heller), Mergui Archipe- 

 lago (de Man), banks of the Hooghly, the mud-fiats of Arakan, 

 Tenasserim, and Mergui (Alcock). 



- 6. Leander, sp. [ 



(Plate xviii, fig. 3.) 



Seventy specimens from Dhappa, near Calcutta, collected in 

 slightly brackish water. 



These specimens are all young, the largest are 23 or 24 mm. 

 long from tip of rostrum to end of telson, but the majority are 

 still younger and of different size. They belong to the group of 

 L. styliferus^ M.'Edw.=longirostris^ H. M. Edw. {Hisi. Nat. Crust., 

 ii, p. 394), L. tenuipes, Hend., L. japonicus, Ortm., L. carinatus, 

 Ortm., L. hastatus, Auriv., etc., but they show differences from all 

 these species. I suppose, however, that these differences are 

 juvenile characters and I therefore do not wish to describe these 

 specimens as a new species, for probabty they will later prove to 

 belong either to L. styliferus or to L. tenuipes, the former of which 

 inhabits an estuary of the Ganges, the Sunderbunds, Mergui, the Gulf 

 of Martaban and Karachi, while the second has also been observed 

 in the Gulf of Martaban, at Madras and at Bombay. 



The rostrum, the distal half of which is upturned, exceeds 

 the antennal scales by one-third or one-fourth of its length, but in 

 the youngest individuals it hardly reaches beyond them. The 

 basal crest, which reaches to the end of the first joint of the 

 antennular peduncle or to the middle of the second, is usually armed 

 with six, more rarely with seven or five teeth ; these teeth are equi- 

 distant or the first is a little farther distant from the second than 

 the following from each other, and the first tooth is situated just 

 above the orbital margin or, just behind it, on the carapace. There 

 is but one apical tooth ; only in one specimen was a trace of a 

 second observed by means of the microscope ; the lower margin 

 carries usually five, more rarely six or four teeth; in the youngest 

 specimens there are often only three. 



Branchiostegal spine a little larger than the antennal spine. 

 Abdominal segments not carinate ; in one of the largest specimens, 

 the carapace of which is 9 mm. long, the rostrum included, and 3*9 



