196 AMEEICAN JOURNAL 



ON A NEW CALIFORNIAN HELICOID LAND SHELL. 



BY J. G. COOPER, M.D. 



D^DALOCHILA Harfordiana, Cooper. — Plate 17, fig. 8. 



Sp. ch. D. testa Isevi, discoidea, planulata, translucente, luteo- 

 cornea ; anfr. 6, superne planatis, lente accrescentibus, ult. an- 

 tice breviter defiexo ; umbilico lato, ad apicem pervio, anfr. 5- 

 monstrante ; apert. obliqua, lunato-ovali ; perist. superne de- 

 presso, albo, incrassato, dentibus duobus inflectis, uno supra 

 medium parietis externi, altero basali ; marginibus callo valido 

 junctis ; dente crasso triangular! in medio parietis interni, ob- 

 lique inflecto, subhorizontaliter sito ; diam. maj. 0*40, min. 0'35, 

 alt. 0-16 cent. poll. Angl. 



Animal albidum, dorso tentaculisque oculiferis nigris, pede 

 longo postice cuneiformi. 



ITab. — Fresus County, California, in sylvis Big Trees dictis, 

 alt. 6500 ped. Angl. supra mare, lat. 37° N. Invenit beatus 

 W. G. W. Harford. 



Specific characters. — Shell smooth, discoid, flattened, translu- 

 cent, yellowish corneous ; whorls six, flat above, slowly increas- 

 ing, the last a little deflexed near the end ; umbilicus broad, 

 pervious to the apex, showing five whorls ; aperture oblique, 

 lunate-oval ; peristome depressed, white, thickened, with two in- 

 flected teeth, one above the middle of the external wall, the 

 other basal ; margin joined by a thick callus ; a strong triangu- 

 lar tooth on the middle of the body-whorl ; obliquely inflected 

 and nearly horizontal ; diam. maj. etc. 



Animal white, the back and eye-bearing tentacles black, foot 

 long, posteriorly wedge-shaped. 



Remarks. — This is the first of the genus found in California, 

 and is very interesting in many particulars. Above and be- 

 neath it almost exactly resembles D. polygyrella, Bid. and Cp., 



