( 



HANNIBAL: CALIFORNIAN FKESHWATER MOLLUSCA. 147 



from the Rocky Mountains and Michigan. The original specimens of 

 solida and apicina came from the present site of Portland, Oregon, or 

 thereabouts, several hundred miles from the nearest point from which 

 miricularia has been recorded. According to the figures and original 

 description the types of these two resemble the forms of auricularia 

 only superficially, but agree closely with the Lymnma, later called by 

 Lea L. hulimoides, under which name this species has been more 

 commonly known. 



Not subsequently recognized : 

 Limncca homhycina, 'Lunge,' Wood and Raymond, 1891 (nude name). 

 San Francisco County, California. 



Family A:N"CYLID^, H. «& A. Adams, 1855. 



Shell of small size, patelliform, crepiduliform, or planorbiform, 

 sinistral or dextral, apex of patelliform genera elevated, medial or 

 posterior, and generally more or less inclined to right or left, spire of 

 planorbiform genera more or less planiilate, aperture normally simple ; 

 animal sinistral, hermaphroditic, tentacles stoutly triangular, buccal 

 plate with accessory lateral jaws, foot large and oval; habitat lakes 

 and streams. 



Four sub-families as follows: — 



Sub-family LyEVAPECm^, n.sub-fam. 



Shell usually large for family, depressed - patelliform ; habitat 

 chiefly lacustrine. 



Genera: Lavapex, Fisherola, Lanx ?,\\\)-ge\\. Walkerola. 



Sub-family ANCYLIN^, s.s. 



Shell small or of moderate size, elevated-patelliform ; habitat 

 lacustrine and fluviatile. 



Genera : Ancyliis, Zalophancylus, Lanx s.s., Loivapex sub-gen. Ferrissia, 

 Gundlachia sub-gen. Kmcaidilla. 



Sub-family LATIIN^, n.sub-fam. 



Shell small or minute, crepiduliform ; liabitat chiefly fluviatile. 

 Genera: Latia, Gundluclda s.s., JSeoplanorbis sub-gen. Amphigyra. 



Sub-family NEOPLANORBIN^, n.sub-fam. 



Shell minute, planorbiform ; habitat fluviatile. 



Genus, Neoplanorlis, s.s. 



The genera and species of this family are characterized by their 

 very limited distribution in contrast to nearly all the other aquatic 

 Pulmonata. This, with the simple form and the fact that the 

 distinctive characters lie chiefly in the outline, microscopic sculpture, 

 and position of the apex, has led to a lumping in the genus Ancylus of 

 a wide variety of species whose resemblances are due rather to parallel 

 specialization than close affinities. 



