NO. 5 CLARK: ECHINI OF WARMER EASTERN PACIFIC 281 



primaries are disproportionately stout yet have a purplish tint. Such indi- 

 viduals are probable hybrids. A critical study, in a marine laboratory, of 

 cross fertilization between the two species would yield interesting, perhaps 

 important results. 



Distribution. — The range of purpuratus is given by Mortensen as 

 from Cedros Island, Lower California to Vancouver Island, with a 

 dubious southern limit at La Paz and an equally dubious northern limit at 

 Sitka. He considers it strictly littoral with 20 meters apparently as the 

 bathjanetric limit. The Velero has secured specimens at 46 stations, of 

 which the northernmost was at Boiler Bay, Oregon, the southernmost at 

 Petatlan Bay, Mexico, Lat. 17° 32' N. As the only other stations south of 

 the United States at which purpuratus was secured are at or near Cedros 

 Island, the Petatlan Bay record needs confirmation. Neither the Albatross 

 nor the Templeton-Crocker Expedition took purpuratus in the Gulf of 

 California, or near La Paz. The specimens labeled Petatlan are undoubt- 

 edly purpuratus but, as in the case of franciscanus, the locality is hard to 

 credit. As for the bathymetrical range of the species, there can be no doubt 

 that it is greater than supposed for the Velero took it at several stations in 

 water ranging from 15 to 88 fms. These were young individuals, however, 

 and it is probable the normal habitat of the species is above 15 fms. 



T3,';^^._U.S.N.M. No. 2495. 



Type locality. — San Francisco, California. 



Depth. — Littoral to 88 fms. 



Specimens examined. — 498 specimens from 46 stations. 



Family EchinometHdae 



Echinometra oblonga (Blainville) 

 Plate 45, Fig. 24 



Echinus oblongus Blainville, 1825, p. 95. 

 Echinometra oblonga Blainville, 1834, p. 225. 



Echinometra mathaei oblonga Mortensen, 1943a, p. 393, pi. 48, figs. 1-20. 

 The status of this species or form of Echinometra is so perplexing that 

 no two writers seem to have just the same opinion on the matter. Morten- 

 sen's treatment of the problem is entitled to the greatest respect, for his 

 wide experience, extraordinary industry and unusual skill in wrestling 

 with such a situation are beyond compare. The only reason for not accept- 

 ing his conclusion outright is that mathaei does not occur in the Eastern 

 Pacific whereas oblonga does, and there it intergrades with VanBrunti 

 in a perplexing way. The Velero collection contains Echinometras which 

 seem to be oblonga in its most typical form, high, elongated, well-rounded 



