HANNIBAL: CALTFOKNIAN FRESHWATER MOLLTTSCA. 183 



i Pachtchilus Lawsoni, n.sp. PI. VIII, Fig. 23. 



f Shell slender-conic, spire attenuate and regularly tapering, whorls 



very long and appressed, without a distinct periphery, normally 

 ' smooth, but sculptured forms with several ridges of even magnitude 



crossed by plications, aperture but slightly sinuate and produced 



below; habitat apparently lacustrine, at least in part. 

 Length 27, breadth 10, altitude of body-whorl 12 mm. 

 Miocene : Contra Costa Lake beds, California. 

 i Berkeley Hills, California; near Bald Peak (types) (H. Hannibal) ; 



same locality (D. A. C. Lawson, Dr. J. C. Merriam, et al.); Grizzley 

 : Peak (Dr. A. C. Lawson, Dr. J. C. Merriam, et al.) ; north flank of 

 I Kuin Peak (Dr. J. C. Merriam, et al.). 

 < Named after Dr. A. C. Lawson, of the University of California. 



Pachtchilus Drakei, Arnold & Hannibal, n.sp. PI. VIII, Tig. 26. 



Shell large, averaging about 45 mm. in altitude, elevated-conical, 

 whorls long and slightly convex, sutures impressed, periphery 

 rounded, aperture ellijDtical, outer lip sinuate; habitat apparently 

 lacustrine, at least in part. 



Altitude 45, breadth 14, altitude of body- whorl 12 mm. 



Eocene : Tejon formation (local freshwater beds), Washington. 



Little Falls, Washington ; Bluffs along Olequa Creek at bend 

 below town (H. Hannibal). 



Only a single specimen, evidently syntonically deformed, is at 

 hand. The sculpturing consists of about twelve rugose plications 

 crossed by an equal number of spirals. 



Named after Dr. IS". F. Drake, of the Department of Geology, 

 Stanford University. 



Superfamily RISSOIDE^ (H. & A. Adams), 1854. 

 Aside from the marine RissoidiB, Kissoinidse, Skeneidte, and 

 Hydrobiidae, and the terrestrial Pomatiopsidae, the Eissoids include 

 two aquatic families — the Amnicolidse, Tryon, 1862 (-f-Fluminicolinaj, 

 Clessin, 1880, Lithoglyphinse, Tryon, 1883, and Paludestriuida;, 

 Newtoil, 1891), and Bulimidse, nom. nov.^ (Bythiniinae, Tryon, 1863). 



^ Type genus Btilinms, Scopoli (Bithynia, Leaeh, Bijthinia and BWiinia of 

 authors). The name has not come into general use, but as may be seen 

 from the following is necessarily applicable. 



1757. Adanson, Histoire NatureUe du Senegal, Coquillages, p. 5, pi. i, 

 described and figured " Le Bulin, Bulinus " , from the fresh waters of 

 Africa. This is one of the physiform Planorbidfe. 



1777. Scopoli, Introductio ad Historiam Natiiralium, p. 392, proposed 

 ' Btiliiiius, Adanson' for the four aquatic and amphibious species of the 

 Linnsean Helix, viz. H. putris (Succinea initris), H. fragilis {Lymnaa 

 stagnalis), H. stagnalis {Lymncea stagnalis), and H. tentaciila (Bythinia 

 tentacula). The diagnosis is not that of Adanson's Bulinus, which is not 

 mentioned. No reference is given to where Adanson may have used 

 Bnliimis. 



1781. Miiller in De7- Naturforscher, pp. 1-20, described the anatomy of 

 " der Perlen-Blasen " (Physa fontinalis), and revived Adanson's Bulinus, 

 ostensibly for the physiform section of his genus Planorbis of the preceding 



VOL. X. — OCTOBER, 1912. 13 



