334 AMERICAN JOURNAL 



Having critically examined, with the greatest care and micro- 

 scopical analysis, at least 20,000 AYestern North American lira- 

 pets, my conclusions will not be regarded as hasty, though 

 they will, doubtless, often prove to be erroneous. 



A. patina, the standard Northern limpet of the AV. Coast, was 

 described by Dr. Gould as Lottia pintadina, with the accuracy* 

 and enlarged discrimination which characterize all his writings, 

 and make them to the student so refreshing a contrast to the 

 careless diagnoses of many authors. The following are the 

 principal varieties : — 



Var. a. pintadina. The analogue of the N. Atlantic A. ies 

 tudinalis, and of the Gulf A. mesoleuca. Large, flat, open 

 Apex subcentral. Color tesselated with white and ashy 

 brown olive, in various proportions. Inside, the shell is gen 

 erally of porcelainous white, with a squarely tesselated border, 

 in which sometimes the light, sometimes the dark predomi 

 nates. This variety includes A. tesselata, Nutt., and diaphana 

 Nutt., (but not A. diaphana^ Eve., which= A. mesoleiica ;) also A 

 verriculata, Eve. It is known from A. mesoleuca by the pre 

 vailing ashy and white, rather than green, tinge ; and also, as 

 well as from A. testudinalis, by the very fine, sharply raised, 

 distant striae, with interspaces very wide in proportion. The 

 "spectrum" is sometimes dark, sometimes light brown, with 

 indistinct outline, sometimes with a few light spots, or nearly 

 white. In the Southern specimens, the white sometimes 

 changes to a rich tortoise-shell. 



Var. h. strigillata: { = A. strigillata, Nutt., pars: pars= A, 

 pelta, jun.) Part of the shells thus grouped by Gould, "mar- 

 ginal rim narrower," may also be A. pelta, ^MXi. The colors 

 run into stripes, radiating and bifurcating. Under ordinary 

 circumstances, this variety is not so elevated as A. pelta ; has 

 not its feint, swelling ribs; but displays, instead, the typical, 

 sharp, distant striae; and has a wider margin: but young 

 shells, with the outside abraded, are very difficult to determine 

 or to separate from A. strigatella of Cape St. Lucas ; q. v. in 

 Ann. Nat. Hist. 



Var. c. Cumingii. (-f- A. mamillata, Nutt. non Esch. nee 

 Mus. Cuming ]iodi\Q:+ A.fenestrata, Nutt. -f J., verriculata^ Eve. 

 -\-A.cinis, Eve.;=J.. scutum, Esch., ?non D'Orb.) In this 

 group, the shell is more raised and pointed anteriorly, with a 

 broad black margin. The fine large shells are A. Cumingii, 

 Eve., from "Valparaiso, Cuming f^ but Mr. C. expressly stated 



* Unfortunately, the "deep emerald green" of the descriptions seems 

 to have been added from the Gulf species, A. mesoleuca, specimens of 

 which, along with varieties of A. patina, were sent to me by Dr. Gould, 

 as representing hxs, pintadina. 



