208 MAZATLAN UNIVALVES 



? + Patella Nuttalliana, Rve. Conch. Ic. pi. 30, f. 81, a, b. 

 ? + Patella Cumingii, Rve. Copik. Ic. pi. 16, f. 37, a, 1. (Val- 

 paraiso, Cuming.) 



? + Patella diaphana, Nutt. non Rve. (v. supra, p. 203.) 

 =Lottia pintadina, (pars,) Gould, loc. cit. in p. 203. 

 Comp. Patella clypeater, Rve. (as of Less. Voy. Coq. p. 419) 

 Condi. Ic., pi. 16, f. 37, a, b, (Valparaiso, Cuming.) 

 I have the authority of Mr. Nuttall, after a careful collation 

 of his specimens and those of Dr. Gould, for placing together 

 his species above quoted. The ordinary form of the shell 

 greatly resembles A. mesoleuca, but without the green tinge. 

 The pattern, which distinguishes many of the above species, 

 often changes in the same shell. Whether the shells of JS". 

 and S. America are the same, is not yet decided. The extreme 

 form is a large solid white shell, with a broad black rim. To 

 this belong the only two specimens found in the Mazatlan 

 collection. Mr. Heeve, who most obligingly named the Maz- 

 atlan limpets according to his monograph, affiliated these, and 

 some of the dark-margined specimens of A. mesoleuca as their 

 young, to P. striata, Quo?/ fy Gaim. Their species is different ; 

 but the young are most probably his own P. striata, sp. 99, from 

 the G-allapagos. The A. scutum of J?sck. is quite different 

 from the large flat shell with a rich metallic lustre, which often 

 goes by that name in collections ; this occurred in abundance 

 at S. W. Mexico, P. P. C., and is from Monterey, Mus. 

 Cum. The largest Mazatlan specimen measures long. 1*5, 

 lat.V2&, alt. '57. 



Hab. Sitcha, Eschscholtz, Wosnessenslci. Kenai Bay, do. 

 Aleutian Is., Unalashka, Kastaljskilugvx Bay, Schantar 

 Is., Middendorff California, passim, Nutt all. Monterey, 

 San Diego, Lieut. Green. Mazatlan ; 2 fresh sp. ; L'pool 

 (M (?) Chili, Bolivia, Peru, D'Orligny. 

 Tablet 1007 contains the most characteristic specimen. 



266. ACM^A PEESONA, 



Esch. Zool. Atl. p. 20, pi, 24, f. 1, 2. Mid. Hal. Ros. pt. ii. 



p. 36, pi. 1, f. 3. 



+ Jun.=A. radiata, Esch. loc. cit.. p. 20, no. 8, (teste Mid.*) 

 + A. ancylus, Esch. loc. cit. p. 20, no. 10, pi. 24, f. 4 bis, 6. (do.) 



* Philippi however (loc. cit. supra) regards A. radiata and A. ancylus as 

 forming a different species not from .N". America, but from Chili. 



