660 PROCEEDINGS OF TEE NATIONAL MUSEUM. vol. 48. 



treme good fortune to secure a Haliotis, although a small and some- 

 what immature specimen. Upon showing this to Doctor Dall, he at 

 once pronounced it to be the true Haliotis pourtalesii, as the sight of 

 the specimen itself refreshed his memory of the example taken so 

 many years ago by Pourtales at about the same locality. A com- 

 parison with the Galapagos specimens above referred to immediately 

 demonstrated the fact that the Atlantic and the Pacific "pourtalesii" 

 were not the same, but, upon the contrary, very distinct species. 



The importance of an east American representative of this essen- 

 tially Pacific genus warrants a new description made from this unique 

 specimen, now in the Museum collection (Cat. No. 271601). I give 

 the following description and figure. The Galapagos Island species 

 must receive a new designation. I take much pleasure in naming 

 it in honor of Doctor Dall. 



HALIOTIS (PADOLLUS) POURTALESII Dall. 



Plates 45 and 46, upper figures. 



1881. Haliotis pourtalesii Dall, Bull. Mus. Comp. Zool. Cambridge, vol. 9, No. 2, 



p. 79. 

 1889. Haliotis pourtalesii Dall, Bull. Mus. Comp. Zool. Cambridge, vol. 28, pp. 



33 and 395. 

 1889. Haliotis pourtalesii Dall, Bull. U. S. Nat. Mus., No. 37, p. 168. 

 1903. Haliotis pourtalesii Dall, Bull. U. S. Nat. Mus., No. 37, p. 168. (Reprint.) 

 1911. Haliotis pourtalesii Henderson, Nautilus, vol. 25, No. 7, p. 81. 

 1914. Haliotis pourtalesii Cooke, Proc. Mai. Soc. London, vol. 11, pt. 2, p. 103. 



Shell somewhat longer than wide. Holes 17, the last 5 open with 

 prominent margins, the closed ones prominent and bulbous. Nucleus 

 consisting of one full whorl, smooth. The characteristic sculpture 

 begins with the postnuclear whorl in very fine spiral fines which de- 

 velop gradually into sharply raised, irregularly waving, spiral threads 

 with finer intercalated threads appearing and continuing to the 

 edge of the aperture. At the end of the second whorl there are 10 

 of these threads between the suture and the line of holes; at the 

 margin of the aperture, 23 to 27. Below the line of holes the threads 

 are more widely spaced, the third one forming a decidedly angulated 

 periphery. Base marked by four equal, equally spaced, spiral threads 

 on the posterior half. Anterior half of the base smooth, excepting 

 a slender spiral sulcus a little within the edge of the wide expanded 

 aperture. The axial sculpture consists of rather regularly spaced 

 lines of growth. Color wax yellow with deeper patches of orange; 

 nacreous shining within. 



Length, 11 mm.; width, 8 mm. 



Dredged about 3 miles off Sand Key, Florida, in 90 fathoms, on 

 sand patches among rocks, on the edge of the " Pourtales Plateau." 



