336 



The general form, direction of the lines of growth and absence of a dis- 

 tinct, concave band, suggest Eunema very strongly. Figure 6 (Clarke 

 and Ruedemann, pi. 10) seems to me to be the true P. bispiralis, 7 and 8 

 apparently something new.'' Figure 9 on the same plate, which Ulrich 

 does not refer to in these notes, seems to the writer to be also quite 

 different from figure 6. 



Pleurotomaria Viola, Billings. 

 In a letter dated April 7, 1906, Dr. Ulrich expresses the opinion 

 that the type of this species, which is figured on Plate 12, fig. 2, of the 

 second part of this volume, is a " Poleumita near P. discors (Sowerby). 

 It is, however," he writes " as you say, a wretched cast, and better speci- 

 m.'ns, if you could satisfy yourself that they were really the same species, 

 might show quite different affinities, with Trochonema, for instance. My 

 opinion is based (1) on the general form of the shell and whorls, which is 

 not unlike that of the higher varieties of P. discors ; (2) on the broad 

 retral bend of the under side of the lip ; and (3) on the indications, 

 obscure it is true, of revolving ridges." 



Pleurotomaria qyclostoma, Whiteaves. 

 " This certainly is an extraordinary type, though its relations are not 

 so far to seek as may appear at first sight. Despite the well-developed 

 slit-band, I am still of the opinion that it does not belong to the Pleuro- 

 tomariidse. Its nearest relatives, however, are among Gotland species 

 referred to Pleurotomaria by Lindstrom. One of these, {P. planorhis, 

 Hisinger) I have already removed to the Euomphalidae under the new 

 generic name Uisingeria. (See Minnesota report). The other relatives 

 are Lindstrom's P. prcetexta and P. togata. In the Hisingeria we have a 

 narrow yet distinct slit-band, but the type is distinguished generically 

 from P. cyclostoma by its planorbiform shell and narrower and more simple 

 band. The P. prcetexta group agrees better with your shell in general 

 aspect and in the position of the carina, that corresponds to the band in 

 P. cyclostoma, but the much better developed, and more sharply defined 

 and concave instead of convex character of the band, together with the 

 closed umbilicus on your species, constitutes sufficient ground for generic 

 separation. In short, I would establish a new genus for P. cyclostoma, 

 another for P. prcetexta, et aliis, and provisionally refer both, with 

 Hisingera, to the Euomphalidse. Undoubtedly all of these shells are 

 related to Euomphalopterus, which I have referred, I fear erroneously, to 

 the Raphistomidae." Ulrich, in letter dated March 19, 1906. 



Pleurotomaria Townsendu, Whiteaves. 

 The type of this species, which was described on page 77 of the second 



