and on Plectopylis, Pollicaria, and Hybocystis. 99 
that feature, and still belonging to Corilla with reference to its 
original typical characters. 
The description of Corilla, with the addition of the pylaic 
plication, will only tend to confusion, and must necessitate the 
formation of another group for Messrs. Adams’s typical forms ; 
while it is evident, from Mr. Gould’s description, that he had then 
no knowledge of the affinity of species not referable to the Pla- 
norboid group; and it would also appear that he was unac- 
quainted with the existence of internal series of pyle. In 
short, Mr, Gould’s description of Corilla is calculated to include 
all Messrs. Adams’s species, adding a feature characteristic of a 
portion only, and, thus altered, is still hampered with the acci- 
dental Planorboid character. Such a subgenus would comprise 
species not truly Plectopylaic; and others which are really so, 
but not Planorboid in form, would be inadmissible. 
In the same paper is described a large and interesting species 
of the restricted genus Alyceus—A. Pilula, Gould, from Hong 
Kong. Another species has lately been described from Java— 
A. Jagori, Yon Martens. The characters given of these two 
species will not permit their assignment with certainty to any 
particular one of the three sections proposed in the ‘ Annals’ 
for March 1859. A third species, A. exul, Bl., assignable to 
the section Charaz, was found during the past year in the Nil- 
gherry range, by Mr. W. T. Blanford, as well as a singular 
new Diplommatina. Neither of these two genera had previously 
occurred to the southward of the Ganges. In the same rich 
locality, Mr. H. F. Blanford had, in a former year, discovered a 
most curious little Cyclostomaceous genus (Opisthostoma, Bl.), a 
specimen of which he has kindly communicated to me. These 
new Nilgherry shells were destined to appear in the ‘Journal of 
the Asiatic Society of Calcutta’. . 
I may here note that I have lately ascertained that the shell 
which | published in the ‘ Annals’ for March 1856, under the 
name of Megalomastoma gravidum, was described in the ‘ Pro- 
ceedings of the Boston Society of Natural History’ for July in 
the same year, as Cyclostoma Pollex, Gould. Mr. Gould pro- 
ceeded, in the same paper, to propose for that shell, in conjunc- 
tion with Rhaphaulus Chrysallis, Pfr., and M. (Hainesia) Myersii, 
Haines, a new group, “ probably generic,” with the designation 
of Pollicaria, This name, if published within a moderate period 
after its submission to the Boston Society, has priority in point 
of time to my generic term Hybocystis, proposed in the ‘ Annals? 
for August 1859 for H. gravida alone, after an examination of 
the animal and operculum. The true structure of the shell of 
Rhaphaulus Chrysallis (discovered by Mr. H. Adams) was made 
known in the ‘Annals’ for April 1856, in which year also 
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