1877-] ON CRUSTACEA FROM SOUTH AMERICA. 653 



9, On a Collection of Crustacea, Decapocla and Isopoda, 

 chiefly from South America, with descriptions of new 

 Genera and Species. By Edward J. Miers, F.L.S., 

 F.Z.S., Assistant in the Zoological Department, British 

 Museum, 



[Eeceiyed June 13, 1877.] 

 (Plates LXVI.-LXIX.) 



The greater number of the Crustacea described in the followin* 

 paper were collected hi Peru, Guiana, Cayenne and Martinique, and 

 were sent by Professor A. Wrzesniowsky, o"f the University of Warsaw, 

 to Dr. Giinther, by whom they were intrusted to me for determina- 

 tion and description. The collection contained also a few Old-World 

 species from various localities, which are described separately at the 

 end of the paper. I have also added descriptions of species belong- 

 ing to the same genera in the collection of the British Museurn, 

 which have hitherto been unrecorded, or known only from names' 

 without descriptions applied to them by A. White, in the • List of 

 Crustacea of the British Museum,' 1847. 



In all, 37 species are noticed, of which 27 are from the New, and 

 10 from the Old World, viz. Brachyura 5 species, Anomura 7 

 Macrura 5, Isopoda 20. Of these 22 appear to have been hitherto 

 undescribed, viz. Brachyura 1 species, Anomura 6, Macrura 2, 

 Iso])oda 13. 



I have carefully noted such variations as I have observed between 

 mdividuals of the same species— the nomenclature having often been 

 needlessly encumbered by the description of nominal species, based 

 only upon sexual or other differences, which the examination of a good 

 series of specimens would have shown to be insufficient. I have 

 also endeavoured to compare the species described with their allies, 

 although in the case of the terrestrial and fluviatile Decapoda and ter- 

 restrial Isopoda this has generally been attempted only as far as theii- 

 congeners inhabiting the same continent are concerned. Many, indeed , 

 of the European Isopoda are only known to me by descriptions so' 

 short and superficial as to render their determination a matter of 

 great difficulty, and their comparison with the New- World species 

 described in the following paper impossible. 



List of the Species described. 

 The names of the species in the collection from Warsaw are in 

 Roman type, those described from specimens in the collection of the 

 British Museum are in italics. 



New-world Species. 

 DECAPODA. 

 Beachyura. 

 Acanthonyx petiverii, M.-Edw. ? Peru. Hepatus chilensis, M.-Edw. Peru 



Neptunus anceps, Saussure. Marti- tubermilattis, Saussure (adulO 



"ique. W. Indies, Cayenne. ' 



Proc. Zool. Soc— 1877, No. XLIIL 43 



