BULIMULUS-ORTHOTOMIUM. 135 



1891, p. 23) is simply frivolous, will be apparent to anyone examin- 

 ing a good series of these shells. 



Figures 17, 18 were drawn from specimens from Derby, Frio Co., 

 Texas ; f. 20, Hidalgo, Hidalgo Co.; f. 12, Corpus Christi, an ex- 

 ceptional form ; f. 22-25, Laredo, Webb Co. 



The limit of its range westward is not yet ascertained, either in 

 Texas or Mexico ; that assigned above being merely what is now 

 known. The localities " Louisiana " and " Isthmus of Tehuantepec," 

 quoted in some works, are erroneous. ' B. alternatus* Forbes, P. 

 Z. S., 1850, p. 54 "from Panama," is an error for B. alternans, a 

 species of Drymceus. 



Group of B. sujjtatus. 



The species of this group and those following are Lower Californ- 

 ian, with the exception of a few found upon the neighboring main- 

 land. Of the latter, B. excelsus occurs at La Paz on the Peninsula, 

 and in a distinguishable variety at Sinaloa (W. M. Gabb) on the 

 mainland. The Costa Rica specimens referred to B. pallidior, prove 

 to be decolored examples of a DrymcKus apparently identical with 

 D. zhorquinemis Angas. B. baileyi occurs at many localities in the 

 State of Sonora, but its occurrence on the Peninsula is very doubt- 



* 



ful. There is therefore but one species of Bulimulus, B. excelsus, 

 which can be admitted on satisfactory evidence to inhabit both the 

 Peninsula and the mainland ; although B. baileyi is very closely 

 allied to some peninsular species. 



Most of the Lower Californian Bulimuli now known, inhabit the 

 mountainous region lying southeast of a line connecting La Paz on 

 the east coast with Todos Santos on the west ; while in the elevated 

 region above the twenty-sixth parallel of latitude the genera Epi- 

 phragmophora, Berendtia and Ccelocentrwn are developed, largely to 

 the exclusion of Bulimuli, although Sonorina extends into this tract. 



The literature of Lower Californian Bulimuli has quite recently 

 assumed extensive proportions, comprising several reports by J. G. 

 Cooper on species collected by naturalists from the Californian 

 Academy of Sciences, published in the Proceedings of that Academy, 

 1891 to 1895; a paper by Prof. Wm. H. Ball (Proc. U. S. Nat. Mus. 

 1893, 639) based upon material from the same source and Binney's 

 types collected by Xantus de Vesey ; a paper by Jules Mabille upon 

 collections made by Diguet, introducing a large number of new and 

 unfigured species, without comparisons with known forms ; two brief 



