HANNIBAL: CALIFOKNIAN FRKSHWATER MOLLUSCA. 209 



Fluminicola^ sub-gen. Ih'athilla, ii.sul)-gen. [Paludina seminalis, 



Hinds). 

 7'^. 3fodoci, n.sp. 

 ■\Pi/r(jHJopsiH Williamsi, n.sj). 

 Cmvinnatia Binneyana, ii.n. {Paludina obiusa, Lea, prouccupicd). 



VlVIPAKOIDE^. 



Viviparuft, suh-gen. Vallina, n.siil)-gen. [Paludina infertexta, Say). 



Idiopoma, sub-gen. Cipanqopaludina, n. sub-gen. [Paludina nialkata, 

 Keove). 

 ]Vlvipartts {Calf inn) Turnpri, n.sp. 

 ]J^. JJ^axhinc/toi) iatius, Arno]d & Hannibal, n.sp. 

 ]Lioplax Andersoniana, n.sp. 



EXPLANATION OF PLATES V-VIII. 



With the exception of the Anodontas and Arnoldina the species illustrated 

 are new or figured for the first time. Characteristic figures of these four have 

 been added owing to the j)revailing uncertainty of their identity. Unless the 

 contrary is stated, figures are approximately natural size. 



Plates V and VI are reproduced from photographs taken by Mr. John Howard 

 Paine, of Stanford University ; Plates VII and VIII from photographs by the 

 writer, through the courtesy of Professor Trevor Kincaid. 



Plate V. 

 (Issued in Part II.) 



1. Anodonta cygnea ivipiora (Say). Pond, Elysian Park, Los Angeles, 



California, p. 125. 



2. .4. cygnea impura (Say) (juvenile). Coyote Kiver, Artesian Belt near 



San Jose, California, p. 125. 



3. A. cygnea (L.). Dalles, Oregon, p. 125. 



4. ^. c//(77!f'a (L.) (juvenile). Umpqua Eiver, Elkton, Oregon, p. 125. The 



individual is just past the impura stage at this side. Cygnea shows 

 almost unlimited variation in this respect, however. 



5. A. cygnea Beringiana (Midd.). Lake Hicaman, Alaska, p. 125. 



6. A. cygnea Beringiana (Midd.) (juvenile). Narrows between Beaver and 



Alexander Lakes, Admiralty Islands, Alaska, p. 125. The specimen 

 is barely past the cygnea stage. 



7. A. cygnea bnpura (Say). x f . Uvas Eiver, Gilroy, California, p. 125. 



Collected in July, probably about three months from the glochidium. 

 All three sub-species are ordinarily identical at this size. 



8. A. cygnea (L.). Glochidium, length 0'35, altitude 0'35 mm. North-east 



shore of Ilhett Lake, near California-Oregon boundary, p. 125. 



Plate VI. 

 (Issued in Part II.) 



9. Arnoldina dejecta (Lewis). San Bernardino Rancho, Arizona-Mexico 



boundary, p. 129. 

 10. Gonidea angiclata Haroldiana, Dall (cotype). Coyote Creek, between 

 San Jose and San Francisco Bay, Artesian Belt, California, p. 127. 

 Through a misundei'standing the original locality was given by Dall as 

 the Guadeloupe Creek. The species formerly occurred there, but was 

 destroyed by sewage about two or three years previous to the time 

 collections sent to the National Museum were made. The variety is 

 not always as large or finely developed as the figure would indicate, but 

 exhibits more or less local variation in this respect. 



