THE STALK-EYED CRUSTACEA OF PERU AND THE ADJA- 

 CENT COAST. 



By Mary J. Rathbun, 



Assistant Curator, Division of Marine Invertebrates, U. S. National Museum. 



INTRODUCTION. 



Anions; the collections obtained by Dr. Robert E. Coker during his 

 investigations of the fishery resources of Peru during 1906-1908 were 

 a large number of Crustacea, representing 80 species. It was the 

 original intention to publish the reports on the Crustacea under one 

 cover, but as it has not been feasible to complete them at the same 

 time, the accounts of the barnacles " and isopods b have been issued 

 first. There remain the decapods, which comprise the bulk of the 

 collection, the stomatopods, and two species of amphipods. One of 

 these, inhabiting the sea-coast , has been determined by Mr. Alfred O. 

 Walker; the other, from Lake Titicaca, by Miss Ada L. Weckel. See 

 papers immediately following. 



Throughout this paper, the notes printed in smaller type were con- 

 tributed by Doctor Coker. 



One set of specimens has been returned to the Peruvian ( iovernment ; 

 the other has been given to the United States National Museum. 



Economic value. — The west coast of South America supports an 

 unusual number of species of large crabs, which form an important 

 article of food. Various smaller kinds, when occurring in abundance, 

 are also eaten, such as the hermit crabs and the so-called hippas or 

 sand hugs. Two species of the latter inhabit Peru. The natives dis- 

 tinguish them by separate names, although carcinologists are slow to 

 recognize their differences. The large and handsome land crab, 

 f'c'nhs, which is rare in collect ions, is said to he abundant in the man- 

 grove swamps, and very palatable. The river shrimp, Bithynis, is 

 one of the most abundant of the forms brought to market ; it soine- 



«Proc. U. S. Nat. Mus., vol.37, no. 1700, L909, pp. 63-74, pis. L6-19, text figs. 1-2. 

 & Idem, vol. 38, no. L729, L910, pp. 79-85, text figs. I 6. 



Proceedings U. S. National Museum, Vol. 38— No. 1766. 



531 



