527 



CRUSTACEA AMPHIPODA. ^'^S' 



■ O 



By Rev. T. R. R. Stebbing. 



Fam. TALITRIDAE. 



Gen. Orchestia Leach. 



Orchcstia plat ens is Krdyer. 



Plate XXI. A. 



1845. Orchestia platensis Kroyer, Naturhistorisk Tidsskrift, Sen 2, vol. i. 

 PP- 304 — "o'^o, pi. 2, fig. 2, a— i. 



Kroyer's specimens were taken on a rocky margin of the river Plate just 

 north-west of Montevideo. The agility with which the animal skips, he says, is so 

 great that it is pretty difficult to catch it. Specimens apparently belonging to this 

 species have been entrusted to me by the authorities of the Copenhagen Museum. The 

 labels show that these examples were taken at the Bermudas, at St Croix (West 

 Indies), and at Beloxi (Mississippi, U.S.A.). Specimens of Orchestia agilis S. I. Smith, 

 from the east coast of the United States, have been given me by my friends, Canon 

 Norman and Mr S. J. Holmes. These also in my opinion should be included in 

 Kroyer's species. 



Now, after much hesitation, I feel constrained to increase its range by applying 

 the name to the specimens taken by Mr Perkins at an elevation of 3000 feet and 

 2000 feet respectively in the Sandwich Islands. At the greater height there was but 

 one example, labelled " Kona, Hawaii." The others were labelled " Oahu " and 

 " Honolulu," and " Lanai." Others were labelled, without specifying elevation, 

 " Waianae Mts., Oahu, shrimps in dead wood." 



The eastern specimens differ to a slight degree from the western in having the 

 second antennae more slender, with flagella not always limited to thirteen or fourteen 

 joints, one of the female specimens having twenty-three, and one of the males twenty- 

 four joints ; also the first gnathopods of the male have the distal part of the sixth joint 



