60 E. Billings on the Genus Athyris. 
least, the name Athyris does not appear to be very inappropriate. Mr. 
Davidson still retains it, not only for those which have the foramen con- 
cealed, but also for those with it open. It appears probable that the 
genus ‘will sooner or later be sub-divided, and in that case Athyris might 
be retained for the species with closely ineurved beak, and Spirigera for 
some of the others. I shall give some account of the generic characters 
of this group of shells in another article. The followin rea a 
placed in oe Bohn: provisionally.”— Canadian Journal, fo}, vol. v, 
273, May, 1 
In that paper I described two species with aes beaks, A. 
clara and A, Mata, which, no doubt, belong to the genus. The 
others with perforated beaks, I marked donbtfa 1, thus —A. 
scitula (Hall); A. (?) Clusia, n. sp. ; ze AY, unisuleata (Conrad) ; 
A. (?) rostrata (Hall) ; A. (?) Chive, n 4 
I think it the same as the species called rears Doris by Prof. Hall — 
(18th Reg. _ p. 84, — I doubt that any of the others belong to 
either Athyris r Spiriger 
Afterward Prot Hall (sth Reg. Rep., p. 74) proposed to estab- 
lish a new genus Mertstella, precisely identical with Athyris, as 
re-defined by McCoy, in 1852. His diagnosis reads thus 
“Shells variable in form, oval, ovoid, orbicular or transverse. Valves 
unequally convex, with or without a median fold and sin us; beak of the 
het 5 
ck ace | 
smooth, or with fine conan lines of growth and fine obsolete radia- 
ting striz, which are usually more conspicuous in the exfoliated shell. 
The interior of the — valve is marked by the presence of the longi- 
tudinal septum, and the upper part of the ventral valve by a deep sub- 
stangolar rauscular impression which unites with the rostral cavity.” 
ne I hold that instead of proposing a new genus, he should 
ve retain e original name Athyris ; because his proposition 
apie toa ataivsion of the group, my and according to the laws 
of nomenclature he should have applied the old name to that 
portion for which it is most approgoais = had been done six 
years y Davidson. is new arrangement e. | 
was publiabnd i re-investigated the sabjeck: and perceiving that 
it amounted to nothing more than a restoration of Davidson’s 
* I now think that 4. clara is the same as Prof. Hall’s Meristella nasuta, but 
pe not quite sure that it is Conrad’s species. A. (?) scitula was afterward found 
was not certaio at t ‘time, as will be 
e above figures repr different views of two specimens of a species which 
appears to me to be identical with that figured in the work above cited. It varies” 
greatly in size. The length of the t specim: T have seen is seve 
lines, the greatest width fourteen lines, depth eight lines. The smallest is about 
eo ose and many hed ipreshaeeee iate sizes have been observed to make out 
