210 



in any of the Macrura, has all its terga well developed and in close contact one 

 with another, and ends in a symmetrical tail-fan. Thoracic sternum linear. 

 Rostrum wanting or quite inconspicuous. 



Antennal acicle well developed. Ophthalmic somite more or less exposed. 

 The upper antennular flagellum is more than half the length of the peduncle. 



External maxillipeds not widely separated from one another at base : their 

 exopodite ending in a flagellum. 



The thoracic legs of the 1st pair are equal and massive and chelate : those 

 of the 2nd and 3rd pairs are long : those of the 4th and 5th pairs are very short 

 and are subchelate. 



The abdominal somites (telson of course excepted) have each a pair of 

 appendages. 



The gills are modified trichobranchias. 



If Pomatocheles Miers (1879) should prove to belong here, the family name 

 will have to be altered accordingly. 



Key to the Indian genera of the family Pylochelida3. 



I. The external maxillipeds are chelate. The hands of the 1st pair of 

 thoracic legs are dorsally flattened and can be juxtaposed along 

 their perfectly straight inner edge so as to form together an oper- 

 culum that tightly closes the orifice of the cavity in which the 

 animal lives ... ... ... ... ... PTLOCHELES. 



II. The external maxillipeds are non-chelate. The hands of the 1st 



pair of thoracic legs are subcylindrical ... ... ... PARAPTLOCHELES. 



Glaucothoe, of which a small specimen, with a decided larval cast, has been 

 dredged by the " Investigator " off the N. Maldive Atoll in 719 fathoms, agrees 

 with the Pylochelidas in its symmetry, but differs in the following particulars : 

 the abdomen, though perfectly segmented and having all its terga properly 

 formed and in contact one with another, is folded on itself : the thoracic sternum, 

 though narrow, is not linear : the large chelipeds are unequal : all the abdominal 

 somites, except the first, have a pair of appendages: the gills appear to be 

 phyllobr anchiaa . 



PTLOCHELES, A. M. Edw. 



Pylochelet, A. Milne Edwards, Ball. Mus. Comp. Zool. VIII. 1880, p. 38 : Milne Edwards and Bouvier, Mem. 

 HUB. Comp. Zool. XIV. 1893, p. 17. 



As pointed out by Milne Edwards, this genus marks the connexion between 

 the TholossinidsB, and the typical Paguridse. Pomatocheles Miers (1879) is closely 

 allied and perhaps identical, as also is Chiroplatsea Spence Bate. 



