THE NAUTILUS. O 



affected, at least the ten specimens which are now in my possession 

 were all more or less, and ihat, too, without regard to size. 



It seems quite probable that Conrad's P. antrosus from Randon's 

 Creek, near Claiborne, Ala., is identical with this form. If so, and 

 the form is worthy of varietal recognition, it would have priority 

 orer Haldeman's name. 



Conrad never figured his species, and unfortunately gave no dimen- 

 sions in his description. His specimens seem to have disappeared, 

 and according to Tryon, in 1870, Conrad himself had forgotten all 

 about it. 



It is possible, however, that some of the original lot found their 

 way to Europe, as the species was catalogued by Beck in 1837 as 

 being in the collection of Prince Christian Frederick (Index Moll., 

 p. 118, 1837). Whether these specimens are still in existence I do 

 not know. 



III. Var. CORRUGATUS Currier, pi. I, fig. 10. 



Planorbis hicarinatus var. corrugata Currier, List of the Shell- 

 bearing MoUusca of Michigan, p. 8, 1868. 



This form was never described by Currier, who simply gives the 

 locality as Perch Lake, Kent Co., Mich. 



The figure is drawn from an authentic specimen (No. 3993, Coll. 

 Walker), received from the late Dr. De Camp, who, in his Michigan 

 Catalogue, described and figured several of Currier's species, but 

 unfortunately neglected this one. 



I have never seen but the single specimen from this locality, and 

 do not know whether any more like it were found or not. 



The form is peculiar in the strong, transverse plications, which 

 extend entirely around the whorl, and are scarcely interrupted by 

 the well-developed, superior and basal carinations; towards the aper- 

 ture, however, they become less distinct. The revolving, incised 

 lines are also deeply cut, and in this feature the form is similar to 

 the var. striatus of Baker. It is altogether the most heavily sculp- 

 tured form that I have seen. The specimen figured is rather small, 

 measuring 9 mm. in diameter and 5 in height. The body whorl 

 immediately in front of the aperture is 3 mm. in height. Individual 

 specimens of var. striahis Baker from Long Lake, Grand Traverse 

 Co.; Dead River, Ives' Lake, Mountain Lake, Little Lake and 

 Howe Lake, Marquette Co. ; Orciiard Lake, Oakland Co., and Mud 

 Lake, Montcalm Co., Michigan, and Gelot's Lake, New Sweden, 



