'*'i';'9a^''] PROCEEDINGS OF ?rilE NATIONAL MUSEUM. 379 



Gulf, wlieic the saline, sterile, and sandy elements i>revail. Occasional 

 examples of several species of the mainland forms oi Arionta also fur- 

 nish illustrations. In the sculpture of the South American Bulimi we 

 find this character modified and carried to extreme elaboration until 

 the shaj^reened surface is attained as in the ]*eruvian B. proteuH and 

 B. mutabiiis (from Santos "under stones"). It will readily be seen 

 that a form whose area of distribution includes subareas, where the 

 (environmental factors are varied to the extent of oi)])osite or nearly 

 opposite, as well as intermediate conditions, would exhibit extreme as 

 well as a multitude of intermediate and what may be regarded as con- 

 necting facies or characters. 



B. nux Brod., Sby., veutricose variety = Keeve'8 tyix'. 



Several examples, Charles Island (Nos. 104822, 104003, and 122856). 



This is the Reeve type of ma; a more ventricose, nnicli larger, and 

 freer growing form than the typical and original nux of Broderip. 

 The color, etc., quoting liceve, is "olive-brown stained Avith rusty red; 

 the a])erture is frequently compressed at the sides so as to give a 

 square aspect." Some examples hint, in the matter of color, at dark 

 cafeau-lait. The color is sometimes a dark reddish-brown; of No. 

 104822 there are three specimens; No. 1040(»3, two; these are rather 

 globose, and coarsely sculptured; of 122850, there are five examples, 

 all in good condition. 



It is apparently an intercised asi)ect of this ventricose variety (i. e., 

 lleeve's type of mix) that has received the names of asperatus from 

 Albers, and incrassatus from Pfeififer (Mus. No. 23277). Reibisch 

 gives a figure of Pfeifter's species in i)]ate 1, 4«, and adds a varietal 

 name to the same of sulcatus, figs. 4& and 4c; while his figure 4^Z is 

 given as incrassatus \iLv\ety=nnciformis Petit, which is i)robably cor- 

 rect. Reibisch's figure 3, ])1. 1, of aspcratus Albers, indicates the pro- 

 priety of its connection with the above. 



***** 



B. nux, el<»ngate<l variety. 



Charles Island; several examples (Mus. Nos. 118573, 122855, and 

 23277). 



This is an elongated form of nvx, sometimes strongly longitudinally 

 ribbed, and i)robably includes verrucosus Pfr., as a variety. Nos. 

 118573, two exanii)les, ]ioint toward P., nq/ulosus. Some forty or fifty 

 examples in addition to the foregoing numbers, are in the National 

 collection. 



B. nux, variety witli distorted mouth. 



Charles Island; several (Mus. No. 118571). Parietal callus pro- 

 duced, forming a continuous peristome. Columella distorted or twisted. 



