On Gasteropodous Mollusca from the Gulf of Suez. 121 
anyhow i must be kept clear and distinct in the mind in 
order to make progress in scientific zootomy. 
While protesting er the abandonment of the very use- 
ful, nay, necessary term “ homology,” I accept with pleasure 
Mr. Lankester's new terms, and thank him very cordially for 
this latest contribution to pileo anatomy. 
IX.—On some Genera and Species of Gasteropodous Mol- 
lusca collected by Mr. M‘Andrew in the Gulf of Suez. By 
ARTHUR ADAMS, F.L.S. 
Mr. M‘AnprEw jain submitted to my inspection numerous 
small and obscure forms of marine gasteropodous Mollusca, 
for the purpose of identification, I hes made a careful exa- 
mination and comparison of them, to assist him in his re 
searches into the geographical dotibution of Mollusca, udi 
have included the results in this paper. 
Fam. Rissoidz. 
Genus CERATIA, H. & A. Ad. 
C. pyrgula, A. Ad. 
C. testa turbinato-turrita, imperforata, alba, tenui, nitida, semi- 
opaca, spira apice obtusa ; ; anfract. 5, convexis, su pro ; 
apertura ovata, antice vix effusa et subdilatata ; labio arcuato, 
acu ag 
. Gulf of Suez. 
bs turreted, turbinate, wana ue white shell, with e 
d of the spire very obtuse, and with the aperture som 
hat effuse and dilated anteriorly. 
Genus MICROSTELMA, A. Ad. 
M. concinna, A. Ad. 
M. testa ovato-turrita, imperforata, alba ; anfraet. 7, planis, postice 
angulatis, supremis longitudinaliter plicatis, plicis rectis, validis, 
sequalibus, interstitiis transversim striatis ; anfractu ultimo magno, 
plicis evanidis; apertura oblongo-ovata, antice producta, effusa ; 
labio areuato, simplici; labro postice ad suturam angulato. 
Hab. Gulf of Suez. 
The only other shell I have seen resembling this somewhat 
worn specimen found by Mr. M'Andrew is Microstelma de 
. Ad., from the Gotto Islands, in Japan (Ann. & Mag. Nat. 
Hist. 1863, xi.p.348). The nucleolar whorls are o eabintandicly 
