Guppy Reprint 
17 
165 
Pa^e 37 
Corbula pisiim ? Sow. 
Gastrochaena ovata Sow. 
* Pholadidea calva Gray 
T Lunulites sp. . . . . . . . . \'N 
Cellaria saliconiia Pallas . . . . R 
T ? Discopora sp. . . 
? Eschara sp. 
(VN. very numerous. N. numerous. R. Rare.) 
In addition the fos.sils enumerated in the foregoing 
li.st there are a few small bones, probably of fishes, and 
a .single tooth has come to light. Crustacea are repre- 
.sented b}' Balani and b}' fragments of brachyurous 
decapoda. There are also a few spines and fragments 
of echinoderms. 
The shells marked * in the preceding list are known 
to me b\" recent examples to be still existing in neigh- 
boring seas. Those marked f are species unknown to 
me either from published works or specimens. — Ostrea 
aiadlata is, I believe, a shell of the ea,stern .seas. — Car- 
dium { Papyridea) . This is not the recent C. {Papyrldea) 
ringiculum ; it is however allied to that species, but 
much smaller and thicker. 
It will be observed that there are 27 species known 
as existing in contiguous waters out of a total number 
of 56 gasteropoda, including 2 freshwater shells and 2 
opisto branchs. Then 16 of the remainder, if not 
found in the surrounding seas, are probably existing 
elsewhere. To two of the.se I have assigned the names 
Nassa incrassata and Troclnis granulatus, on account of 
their resemblance to the European species of those 
names, but at the same time with much hesitation. 
The proportion of recent species thus arrived at is 
nearl}’ 80 per cent. ; or 20 per cent, of unknown and 
extinct species, but making due allowance for imperfect 
knowledge, there would probabh" remain at least 10 per 
cent, of extinct species of Gasteropoda. 
With regard to the Conchifera, the proportions are 
nearly the same. There are 22 species out of the total 
of 36 which are certainly known to me to exist in con- 
