202. Dr. E. von Martens on some Species of Assiminea. 
XXIII.—Conchological Gleanings. 
By Dr. E. von Martens. 
[Continued from p. 88.] 
II. On some Species of Assiminea. 
Tuts genus, so well characterized among all operculated Gas- 
teropoda by the position of the eyes near the tip of the tentacles, 
was proposed as early as 1819 (Leach’s manuscript), and has never 
since been seriously opposed; but up to the present time some 
species of it have not been recognized as such, but have been, 
described under the generic name of Realia, Hydrocena, Ompha- 
lotropis, Paludina, Melania, or Paludinella. Realia seems to be, 
and Omphalotropis is, if we take Cyclostema rubens, Quoy and 
Gaimard, as its representative, a true land-shell with two long 
slender tentacles bearing .the eyes on the outside near the base. 
There is no objection to placing these two genera in the family 
of Cyclostemidz, and supposing, therefore, the radula (still un- 
known, as far as I am aware) to belong to the type of the 
Tenoglossa. The genus Hydrocena was founded on a sub- 
marine shell from Dalmatia, H. cattaroénsis, uniting the umbi- 
lical callus and general shape of Helicina with the opercular 
apophysis of Neritina, and agreeing with both in the conformation 
of the radula (Rhipidoglossa), (see Kiister in the ‘ Continuation 
of Chemnitz,’ genus Paludina, pl. 13. figs. 28, 33; and Troschel 
‘ Gebiss der Schnecken,’ vol. 1. pl. 6. fig. 1). The name Hydrocena 
can henceforth be applied only to shells showing the said charac- 
ters, or,as long as their radula and operculum are not known, sup- 
posed to do so. Paludina and Melania are, as everyone knows, 
freshwater shells belonging to the Ctenobranchia teenioglossa. 
The genus Paludinella was founded by Pfeiffer in 1841 (Wieg- 
mann’s Archiv fiir Naturgeschichte), for the so-called Zruncatella 
itorea of Philippi, a littoral shell from the Mediterranean, whose 
natural position is not yet clear; the name has been transferred 
by many authors wrongly to the small freshwater Paludina with 
spiral operculum, for which exists the older name Hydrobia, Hart- 
Pedes fulvo-testacei. Long. 4; in. Hab. in Rio Janeiro, a Dom. 
Squires lecta. | 
Desmiphora venosa. Elongata. Caput fuscum, fulvo hirtum, punctatum, 
Antenne robust, pilose, fulvo-brunneze, articulis supra nigris. Tho- 
rax niger, nitidus, crebre foveolatus, lateribus fulvo plagiatis, dorso 
fusco bipenicillato. Elytris juxta basin et latera crebre foveolata, 
fusca, medio plana vix punctata, cinereo-brunnea, apice fusco macu- 
lata; singulis penicillis grossis fuscis, deeumbentibus, una prope basin, 
altera apicem versus, lateribus et parte postica lineis flexuosis elevatis 
cinereo tomentosis. Corpus subtus et pedes testacea, cmereo villosa. 
Long. 33 lm. Hab. in Rio Janeiro, a Dom. Squires lecta. 
