26 



Gulf of Panama* (Faxon), from off Colombo (Alcock), from the 

 Azores, Cape Verdes, south of Madeira and coast of Spain 

 (Bouvier). 



Irish Distribution. — Only a single specimen has been taken 

 in Irish waters. 



Helga. 



S. R. 593—6 VIII '08. 50° 31' N., 11° 31' W., 670-770 fms., 



ooze. Trawl. Temperature at 650 fms., 7-75° C. ; 



Salinity 35-53%^— One, 76 mm. 



Vertical Distribution. — The greatest depth for the species is 



1,076 fms. (S. of Madeira) ; the others range from 675 fms. (o:ff 



Colombo) to 899 fms. (Gulf of Panama). 



Eryonicus, Spence Bate. 

 Eryoneicus, Spence Bate, 1888. Eryonicus, Faxon, 1895. 

 Eryonicus, Alcock, 1901. 



This genus was founded by Spence Bate on a very small 

 specimen 13 mm. long, which v/as taken by the Challenge! near 

 the Canary Islands. He ga"ve to this specimen the name of 

 E. coecus, but, owing to the immaturity of the original of his 

 description, it is difficult to refer adult specimens to the same 

 species with certainty. Faxon, however, identified several 

 specimens taken by the Albatross off the wast coast of Central 

 America as belonging to Bate's species. He gives a very com- 

 plete and detailed account of these specimens, but it is very 

 doubtful whether they really belong to E. coecus. Since then 

 Eryonicus has been taken in several parts of the Atlantic, in the 

 Mediterranean, and in the Indian and Pacific Oceans. 



Though Eryonicus and Polycheles are distinguishable at a 

 glance, yet examination shows that in very many points there 

 is close approximation between the two genera. The chief char- 

 acteristics which distinguish Eryonicus are (1) the extreme 

 inflation of the carapace, which is sometimes almost spherical, 

 and is larger than the abdomen ; (2) the very paculiar form of 

 the renal tubercle of the antennae which is produced to an 

 extraordinary length, nearly equalling the peduncle itself, in 

 the form of a slender cylindrical rod projecting inwards and 

 forwards ; (3) the shortness of the antennuies and antennae 

 which are less than half the length of the carapace ; (4) the 

 shortness of the chelipeds, (5) the almost membranous character 

 of the integument. 



The spiny armature of the carapace and abdomen is on 

 the same plan as in Polycheles, the spines being usually confined 

 to certain definite carinae. Sometimes, however, there are also 

 spines scattered over the intercarinal surface of tha carapace. 



The eyestalks are of the same form as in Polycheles, but they 

 do not so completely fill the orbital sinuses, nor is the outer lateral 

 process so well developed, indeed in small specimens the latter 



*P. granulatua has also been taken at a number of stations near the 

 Hawaiian Islands (Rathbun, 1906.) 



