'642 LOWER CALIFORNIAX BULIMULUS DALL. 



retiec'ted in iiuy nf the vspccimciis. The siu'ciiiiens colkM'ted by Bryant 

 and l^^iseii are of the smooth, or rather not liiannlated variety Icris, 

 Avliieh aeeounts for Dr. ('ooi)er''s inability to harmonize them Avith J>in- 

 ney's description and li^ure. The epidermis is thin and olivaceous, 

 and Dr. Cooper reports the most perfect specimen as beiuf>- streaked 

 with brown, lighter an<l darker, as on />. altcniatii.s. 



The type of B. Xantusi measures 20 mm. long, lOi mm. in greatest 

 width, the aperture 10 by 7 nun. The smooth ones are variable in size, 

 measuring from 18 by 10.5 to 17 by 8.5 mm. I^one of the specimens 

 received from Dr. Cooper show any trace of color markings. B. dUiitale, 

 described by Keeve (Conch. Ic, PI. 47, Fig. 308, November 1848) without 

 habitat, bears from the figure a very close resemblauce to B. Xantusi. 



StHti.m LEPTOBYRSUS Crossr ami Fisclier. 



The type of this section is />. sjnrifer Gabb, but from a study of the 

 species I am satisfied that several of the other species are too closely 

 related to be separated from B. spirifer sectionally, though at first 

 sight they fail to show the characters clearly. The section contains 

 two sets of species, which are separated by the i)resence or absence of 

 the prominent lobe or tlauge on the pillar in the first half of the last 

 whorl, but all the species xiresent occasional individuals which show a 

 ridge here, even if the majority of the conspecific specimens do not. 

 The nuclear whorls are peculiar, and agree closely, especially in the 

 sunken x)osition of the extreme nucleus making a pit or dimple on the 

 apex of the spire; the nuclear whorls have a i)ecnliar and wheiumworu 

 a very shar[) and characteristic sculpture, and most of the species have 

 an extremely similar facies, the most aberrant form being B. arte- 

 viesia, which, however, differs only by its more numerous wliorls, 

 slender form, and the less-refiected peristome. 1 am confident that all 

 these species are genetically connected, and that they sliould be em- 

 braced in one sectional grouj). 



Si'bscctidu A ; \vitli(nit ])romiiuMit lauielhi. 

 Bulimulus (Leptobyrsus) artemesia W. (;. Hiiiiicy. 



Cajje St. Lucas, Xantus, 1 (type) specimen; Sierra Laguna, at 3,000 

 feet above the sea, 2 specimens, Eisen. (Plate i.xxii. Fig. 5.) 



The tyi)e is in good condition; it has eight and a half whorls, of 

 which the first two are obtusely keeled above and the nuclear point 

 small and sunken, Ibrming an apical funicular i)it which is quite con- 

 spicuous. The sculi)ture of the nucleus is like that of the other species 

 already mentioned, of rather sparse fine, sharp riblets. with the wider 

 interspaces more or less spirally engraved. The surface is wrinkled 

 finely, with traces of granulation here and there on the Avrinkles. The 

 peristome is slightly refiected, and inside thickened in the manner 

 characteristic of a shell which has passed the dry season adhering to 

 the bark of a tree. The pillar far within the aperture shows a faint 

 elevated ridge. Traces of epidermis on the shell are pale olivaceous 



