WEST AMERICAN HALIOTIS — BARTSCH 51 



Mr. Sorensen has sent two of these to me, and I find thut they agree 

 in every way with the type but are somewhat smaller. Their meas- 

 urements are, respectively, as follows: Height, 63, 51 mm.; greater 

 diameter, 165, 156 mm.; lesser diameter, 132, 123 mm. The dealer 

 stated that they were very rare, and he believed that they originated 

 from some of the isliinds offshore, probably Guadalupe; we therefore 

 have an additional station, which materially extends the known range 

 of the species. 



HALIOTIS ASSIMILIS Dall 



1878. Haliotis assimilis Dall, Proc. U. S. Nat. Mus., vol. 1, p. 46. 



This strongly inflated, oval species we had in the collection of 

 the National Museum from the region of San Pedro and San Diego, 

 where it was said to occupy rather deep water. Mr. Sorensen's send- 

 ing has extended its known range as far northward as Monterey 

 County. 



HALIOTIS RUFESCENS Swainson 



This species extends from Mendocino County, Calif., to the off- 

 lying islands to the south. The typical race is an important element 

 in the West American abalone fisheries. 



I am recognizing three subspecies, as follows: 



HALIOTIS RUFESCENS RUFESCENS Swainson 



1822. Haliotis rufescens Swainson, Appendix to the Bligh Catalogue, Exotic 



conchology, ed. 2, p. 34. 

 1832. Haliotis californiana Valenciennes, Recueil d'observations de Zoologie 



. . . Voyage Humboldt et Bonpland, vol. 2, p. 267. 



This gigantic race ranges from Mendocino County, Calif., south 

 to Catalina Island. 



The two largest specimens in our collection, U.S.N.M. No. 535758, 

 donated by Mr. Sorensen, yield the following measurements, re- 

 spectively: Height, 87, 76 mm.; greater diameter, 251, 257 mm.; 

 lesser diameter, 213, 218 mm. ; weight, 1,528, 1,062 grams. 



HALIOTIS RUFESCENS WALALLENSIS Stearns 



1900. Haliotis fulgens walallensis Steaens, Proc. U. S. Nat. Mus., vol. 22, p. 140. 

 1921. Haliotis wallalensis Dall, U. S. Nat. Mus. Bull. 112, pi. 22. 



This small northern race was described by Dr. Stearns from 

 Gualala, Mendocino County, Calif. Its narrower shape, less rugose 

 surface, and smaller size differentiate it from the typical race. 



