98 L. A. BORRADAILE. 



CARIDEA. 

 Family Palaemonidae. Genus Leander, Desm. 



11. Leander debilis (Dana), 1852. 



Palaeman debilis, Dana, U.S. Expl. Expd., Crust. I. p. 585, PI. XXXVIII. figs. 6, 7 (1852). 

 Leander debilis, Ortmann, Zool. Jahrb. v. Syst. p. 515 (1890) in part. 



Ortmann (loc. cit.) included under this species, as varieties, several other Leanders 

 described by various authors. Among these was L. longicarpus, Stimps, 1860, which has 

 since been identified by de Man and Coutiere with L. concinmis Dana, 1852. The present 

 collection contains examples of a form allied both to L. debilis and to L. concinnus, though 

 more closely to the former than to the latter. In fact the points of difference between the 

 preserved specimens would certainly be sufficiently small to justify their inclusion in a single 

 species were it not that they exhibit considerable differences in colour and habitat. For notes 

 on these I am indebted to Mr Gardiner. 



The present species has 6 — 9 teeth on the underside of the rostrum and 4 — 6 above, 

 and the carpopodite of the second leg just I'eaches the end of the antennal scale. Its size is 

 rather greater than that of L. gardineri. When alive it is colourless, but has eggs of 

 a brilliant dark green. 



The only locality in which it was found in the Maldives was a kuli surrounded by 

 a mangrove swamp in Landu, Miladumadulu atoll. It was here few in numbers and 

 solitary in its habits. 



12. Leander gardineri, n. sp. 



Under the rostrum of this species are 4 — G teeth, and above it 5 — 6. The second 

 leg of full grown individuals is longer than in L. debilis and its carpopodite exceeds the 

 antennal scale. The size is less than that of L. debilis, the largest specimen being .33 mm. 

 in length. The third flagellum of the antennule resembles that of L. debilis, and not L. con- 

 cinnus, in being free for less than half its length. The colour is intermediate between straw 

 and brown, the eggs being of a darker shade of the same ; the branchiostegites a silvery-white. 



This prawn was found in enormous numbers at the edges of a large fresh-water kuli in 

 Ekasdu, Miladumadulu atoll. Both it and the former species are thus of interest in that, 

 contrary to the usual habits of the genus, they live in fresh water. The allied L. concinnus 

 lives indifterently in fresh, brackish or salt water. 



ISOPODA, ONISCOIDEA. 

 Family Ligiidae. Genus Ligia, Fabr., 1798. 



13. Ligia exotica Roux, 1828. 



Ligia exotica, Roux, Crust. Medit. III. PL XIII. fig. 3 (1828). 



Fairly common throughout the group on boats, ships, wharves, etc. At Mahugudu, 

 Miladumadulu atoll, extremely common all round the shores of the island on the rocks. 

 The specimens from the latter locality are somewhat smaller than those from other places 

 in the group or than those met with in Ceylon or Minikoi, and their colour is different, 

 consisting of a white ground covered with microscopic dark spots, giving a greyish appear- 



