194 The Molluscan Family Planorbidae 



The subgeneric names proposed by Lindholm in 1909 are ignored. These 

 six genera, as listed by Thiele (1931, p. 482) with the earlier names of 

 Lindholm and the new names proposed by Tomlin for the preoccupied 

 names, are tabulated below. 



1. Choa7iomphaIus (SS). Type Choanomphahis maacki Gerst. 



2. Valvatomphalus D. and G. {= Achomwmphalus Lindholm, 1909). Type C. amau- 



ronicus Bourg. 



3. Cryptomphalus D. and G. (non Charpentier, 1837)= Omphalocrypta Tomlin, 1929. 



Tvpe C. cryptoinphahis W. Dybowski 



4. Biangulatiis D. and G. Type Choanomphahis bicarinatus Dybowski 



5. Anomphalus D. and G. (non Meek and Worthen, ISQ^)^ Anomphalodes Tomlin, 



1929. Tvpe C . anomphalus W. Dvbowski 



6. Platybasafis D. and G. {= Sulci) er Lindholm. 1909). Type C. schrc7icki W. Dy- 



bowski 



The value of these generic and group names is debatable. The plate of 

 species in the Dybowski and Grachmalicki monograph docs not show 

 variation enough to warrant any such minute division, and many of the 

 figures suggest individual variation, such as is common among many of our 

 North American species of Helisoma. Possibly the few groups and species 

 enumerated by Lindholm can be recognized, judging from the figures in 

 Fischer's paper (1879, plate 4, figs. 8-10) which are reproduced on my 

 plate 81. Just why all of the Lake Baikal species of Choanomphahis should 

 not be included in the one genus is not apparent from a study of the shells 

 and what little is known about the animals. 



The name Wladislaviidae can not be used because Germain in 1923 

 (p. 190) proposed the subfamily name Choanomphalinae two years earlier. 

 On this page Germain also questions the value of recognizing subgenera 

 for the different species. 



Until the details of the genitalia arc known, particularly the form of 

 the ovotestis, prostate, and the internal conditions of the penial complex, 

 it will be impossible to determine the true position of this group in the 

 classification of the fresh water pulmonates. For the present, the group 

 designation of Germain as a subfamily of Planorbidae should be retained. 

 It is possible, of course, that when the anatomy is known the group might 

 be found to be of family rank, but in that case the name of Germain must 

 be used because it was given at an earlier date than Wladislaviidae of 

 Dybowski and Grachmalicki. 



Genus POECILOSPIRA :\Iorch, 1853 

 Tj'pe by original designation Valimta muUijormis Zeiten 



1853. Poecilospira Morch, Cat. Conch. Yoldi. Type Valvota multiformis Zeiten 



{= Helicites trochiformis Stahl. 1824) 

 1879. Poecilospira Crosse and Fischer, Jour, de Conch.. XXVII, p. 160. Type Valvata 



muUijormis Zeiten. As genus 

 1884. Poecilospira Tryon. S. and S. Conch., Ill, p. 105. Type Planorhis muUijormis 



(Zeiten). As subgenus of Choanomphahis 



Shell (plate 81, fig. 1). Dextral, varying from fiat with depressed spire, 

 discoidal, to trochiform with greatly elevated spire, the last whorl rounded 

 and in the same plane as the body whorl or greatly deflected. Whorls 

 carinated, the carina placed at the upper side of the whorl in planorboid 

 forms and forming a peripheral ridge in the forms with elevated spire. 

 Umbilicus large and conspicuous. Aperture round or lunate, entire and 



