No. 17. 2%e Echinoderms of Peru. By HUBERT LYMAN CLARK. 



The following report, prepared at the request of the Ministerio de 

 Fornento, of the Peruvian Government, as a contribution to the knowl- 

 edge of the aquatic resources of Peru, is for use in connection with 

 marine investigations in that country, though the needs of the general 

 zoologist and particularly of those chiefly interested in the fishes and fish- 

 eries of Peru, have been kept in mind. The keys are therefore as simple 

 as possible and are based, so far as practicable, on obvious external char- 

 acters ; they are consequently very artificial. The report is based pri- 

 marily on the collection of echinoderms made by Dr. Robert E. Coker 

 in 1907-08, and I am glad to express my thanks to him for the oppor- 

 tunity to study the collectio^ and for the use of his field notes and 

 other data. In addition to the species found in this collection I have 

 included all the echinoderms actually known to occur south of the equa- 

 tor and north of 40 S. latitude, and which may therefore be reasonably 

 expected to occur on the coasts of Peru. I have not included any species 

 described from such indefinite localities as " west coast of South Amer- 

 ica," " Chile," " Ecuador," or " west coast of Colombia," unless they 

 have since been recorded from the given coastal area, excepting such 

 rare cases as Holothuria chitensis, where the genus is a tropical (or sub- 

 tropical) one and the species is described as from Chile. The collec- 

 tion in the Museum of Comparative Zoology, which contains many South 

 American species, a large number of which were brought home by the 

 "Hassler" expedition, has been of great assistance. In it were found 

 two new starfishes. 



The Peruvian echinoderm fauna is not a rich one. There are no crinoids 

 known from the region, and only seven holothurians and ten ophiurans. 

 The echini are represented by a dozen species, and the starfishes by 

 twice that number. Clearly the starfishes are the predominating fea- 

 ture, and this would be even more striking if the numerous species de- 

 scribed from Ecuador and Colombia, some of which may ultimately be 

 found on the northern coast of Peru, were included. It is interesting to 

 note that the Peruvian marine fauna is made up of two quite different 

 elements, that from the Panamic region hd that from the Chilean. The 

 latter furnishes all of the echinoderms found* south of Aguja Point, 





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