150 PROCEEDINGS OF THE ACADEMY OF 



it might be considered identical if not for the important differ- 

 ences indicated in the diagnosis. 



Mr. Binney places that species without hesitation in subgenus 

 Lochea, which has the shell represented by calcareous granules 

 only, but remarks that he had not examined the jaw or granules, 

 and, as the types are probably still preserved in the Smithsonian 

 Institution, this important omission may yet be attended to. 



Dr. Gould saj's, in Binney's Terr. Moll. ii. p. 31, " That this 

 animal belongs to the genus Avion there can be little doubt, from 

 the peculiar structure of the tail, as represented in Mr. Drayton's 

 figure, and from the anterior position of the respiratory orifice." 

 He did not examine any specimens with reference to the shell, but 

 figures the dorsal areolae as peculiarly granulated and indented, an 

 appearance apparently caused, as in our species, when in alcohol, 

 by minute reticular subdivisions. The figure represents the tail 

 as acute, though Dr. Gould describes it as " somewhat truncated 

 at tips exhibiting a conspicuous pit which was probably occupied 

 by a mucous gland." As he was no't aware of the existence of 

 this gland in his " Limax" Columbianics, he may have examined 

 specimens of the latter when partly or wholly destitute of the 

 shell (as described by me), and confounded them with Drajton's 

 figure, as alcoholic specimens do not retain all the specific charac- 

 ters. The great similarity of the figure published as of the Avion 

 to that of L. Columbianus makes it probable that some such con- 

 fusion has occurred, the only essential difference being the posi- 

 tion of the spiracle. 



Mr. Try on places this species in Aviolimax, but on what grounds 

 is not stated. This would be justified by the discovery of the 

 shell and generative orifice in alcoholic specimens, but is rendered 

 doubtful by other considerations above pointed out. 



Mr. Drayton's original figure probably represented A. Andev- 

 sonii, though Dr. Gould's description does not agree wholly 

 with it. 



LISINOE DIABLOENSIS. Cp. n. s. PI. 3, fig. G. 1, 2, 3, 4. 

 Helix (indet., near Traskii), Cp., Proc. Cal. Acad. Sc. III. 2G0, 18CG ; 



332, 18G7 (as perhaps a hybrid). 

 II. Diabloensis, Cp., Aruer. Journ. Conch. IV. 221, 1868. 

 Ariontu? Diabloensis, Cp., ibid. V. 205, 207, 1870. 



Sp. ch. Testa depresso-turbinata, infra paullo concava, anfr. vi et dim. 

 ad vii. umbilico amplo, peristomate albo, expanso, satis incrassato, su- 

 perne decline ; colore ex luteo brunnea, intus purpurascens, zona fusco- 



