LOWER CALIFORNIAN MOLLUSCA. I33 



B. BULIMULUS (PALLIDIOR?) VEGETUS AND ITS SUB- 

 SPECIES. 



It has long been a doubtful question concerning two 

 species (or forms) of this group, as to whether they were 

 identical with two South American species (only differ- 

 ing as varieties at most), or were radically distinct and 

 autochthonous. 



The first American describers of species from the 

 peninsula could find no specific differences, or else, con- 

 sidering the great variations in species of this group, did 

 not venture to separate them on comparison with descrip- 

 tions and t3-pical specimens, although Dr. Gould at first 

 considered his B. vegetus specifically distinct from B. fal- 

 iidior. Still later, Binney and Bland described the lingual 

 dentition of the Peruvian B. faJlidior, and had means of 

 comparing that of the peninsular allied form, but did not 

 report any differences between them. 



Since the expedition to the peninsula in 1891, Dr. W. H. 

 Dall, to whom I sent living specimens of the so-called 

 '' B . -proteiis Broderip " from the mountains, has separated 

 the peninsular shell from the South American, without 

 giving any but external differences. It is not strange 

 that without good and numerous Peruvian and Chilian 

 examples we were compelled to agree with the older 

 authors in uniting them, since even Dr. Dall, with numer- 

 ous specimens from both regions, has not ventured to 

 distinguish the peninsular B . fallidior. I am willing to 

 agree to the distinctness of B. monteziiina Dall, but for 

 the sake of consistency must also contend that the other 

 disputed form is also different in North and South Amer- 

 ica, the most northern having already been separated as 

 B. vegetus Gould. 



Still further to show the differences in the species of 

 the unconnected geographical regions it mav be stated 



