NORTH PACIFIC OPHIURANS IN NATIONAL MUSEUM CLARK. 5 



Four other very common species are represented by more than 300 

 specimens each: 



There are 559 different stations represented in the collection, but 

 at 218 of these only a single species of ophiuran was taken and at 

 141 other stations only two species occurred. There are 14 stations 

 at which ten or more species were collected. The average number of 

 species to the station is 2.6, but if there is left out of the account 

 those at which only one or two species were taken the average num- 

 ber rises to 4.8. The largest number of species taken at any one 

 station was at station 4893, which is southwest of the Goto Islands 

 in the Eastern Sea. Here, at a depth of about 100 fathoms, with a 

 bottom temperature of 55.9, the following seventeen species were 

 found : 



Ophiarachnella megalaspis. Ophiacantha pentagona. 



Ophiozona elevata. Ophiacantha rhachophora. 



Ophiozona projecta. Ophiacantha normani. 



Ophiura sculpta. Ophiurases obstrictus. 



Ophiocten charischema. Ophiothrix koreana. 



Ophiomusium simplex. Ophiothrix macrobrachia. 



Ophiodoris pericalles. Ophiomyxa anisacantha. 



Ophiomitra habrotata. Astroceras pergamena. 

 Ophiocamax polyploca. 



This is a much larger number of species than was taken at any one 

 of the Challenger stations, but it does not equal the famous haul 

 made by the Hassler off Barbados in 100 fathoms, when twenty 

 species of ophiurans were taken, and it is far behind the record estab- 

 lished by the Blake at her station 269, off St. Vincent, British West 

 Indies, in 124 fathoms, where twenty- three species of fifteen genera, 

 were collected." It is interesting to note that warm water is not 

 essential, however, to a large and diversified ophiuran fauna, for the 

 next largest number of species taken at one spot was at station 4781, 

 which is near Agattu Island, Aleutians, in 482 fathoms with a bottom 

 temperature of 38.6. Here sixteen species were taken, representing 



& This record was equaled by the Siboga near the Ki Islands, at station 251, 

 where in 114 fathoms, twenty-three species were taken, representing sixteen genera. 

 But while the Blake took a twenty-fourth species at its next station (270), the Siboga 

 found no other ophiurans in the immediate vicinity of its best haul. 



