6 THE NAUTILUS. 



respecting other forms. A number of " Zonites " were included, 

 among them specimens of Z. carolinensis Ckll., and of two new spe- 

 cies, one of about the same size as suppressus, the other larger. Of 

 these an account will be given later. Among the Helices, one of 

 the most interesting forms was labelled " H. ivetlierhyi Bid. var. Don't 

 believe it ! " Upon glancing at the specimens I was compelled to 

 join Wetherby in his scepticism, for the shells are certainly unlike 

 H. tvetherbyi, and belong to quite a different group of species. The 

 first notice of these so-called wetherbyi appeared in a paper written 

 by Mr, Wetherby on the shells of Roan Mountain, and published in 

 the Journal of the Cincinnati Society of Natural History, vol. iv, 

 as long ago as 1881. The paragraph is as follows: 



" Mesodon wetherbyi Bland. — Shells which have been referred to 

 this species occur somewhat sparingly at this locality. Like the 

 specimens from the original station, the shells are covered with a 

 thick coating of dirt, imbedded in the hirsute covering of the epi- 

 dermis, which being carefully washed away leaves the shell of a 

 pale greenish white color. These shells have a lamellar projection 

 on the inferior surface of the peristome much like that of some 

 varieties of T. appressa, and which is a character very distinct from 

 that of the same region in the type. A very careful examination 

 of the genitalia shows them to be much more like those of Triodop- 

 sis. Indeed, looking over the whole field, it seems not improbable 

 that here we have another case of the union of characters of Meso- 

 don with other groups, like that of Stenotrema, mentioned in my 

 notes, No. 1. Mr. Binney says, Terr. Moll., vol. v, p. 301, " Trio- 

 dopsis does not differ from Mesodon or Polygyra in the character of 

 its jaw." Again, p. 306, he says that the genitalia of T. appressa, 

 resemble, in certain features, those of Mesodon sayii=3L diodonta. 

 This shell certainly presents as many features that would ally it 

 to Triodopsis through appressa, as to Mesodon through dentijera. 

 In fact, I am inclined to the belief that the shell is not Mesodon 

 wetherbyi at all, but a distinct species, probably a Triodopsis, and 

 having the closest analogy to M. dentijera Binney, which certainly 

 has some very strong claims to relationship to Triodopsis through 

 T. apjyressa. The station of this species is always in the dirt under 

 and beside rotting logs. It is very sluggish and timid, and very 

 rare." 



It will be seen that Wetherby recognized the Ti-iodopsoid affini- 

 ties of the snail ; but in the writer's opinion it is more nearly allied 



