MOLLUSC A. 
] 13 
C. obscurus, Lesueur. — The Mackerel Shark is often brought 
to the market, and the poorest people consider it fair food. 
Lamna, Cuv. 
L. glauca, Mull. & Henle. — The Dog-tooth Shark, which occurs 
at Java, Japan, and the Cape of Good Hope, is also occasionally 
taken at St. Helena. 
II. MOLLUSCA. 
In Conchology the Island does not offer a very wide field for the 
naturalist’s researches, hut it affords one of extreme interest. 
The extinct land-shells, although described as having some affinity 
with those of the Polynesian Islands, Central America, Africa, 
Mozambique, and the Seychelles, are for the larger part unique, and 
Unmistakably point to the individuality of the Island and its non- 
connexion at any time with the existing continental lands of Africa 
or America. The amount of dredging that has yet been accomplished 
ofi the Island is very small, but the treasures it has yielded to the 
scientific world are quite sufficient to encourage the enthusiastic 
naturalist. My own collection of shells, now in the British Museum, 
Tas been made almost without the aid of dredging, the marine species 
having been picked up on the beach or taken from the rocks a short 
distance below high water. I have therefore been careful to dis- 
tinguish those which I found in a living state, because, until the 
ref d have been found in a similar condition, there exists a probability 
°f their having been thrown overboard from ships. I am most 
fortunate in being able to record the examination of the collec- 
tion by so eminent an authority as Mr. J. Gwyn Jeffreys, who, in 
fhe Annals of Natural History for April, 1S72, gives a list of the 
s Pecies, and writes as follows : — 
“ With the assistance of my friend, Mr. MAndrew, I have 
e xamined a collection of shells made by Mr. J. C. Melliss at St. 
-Helena. Most of the marine shells were picked up on the 
beach, and are consequently in bad condition. The only speci- 
men procured from deepisli water (about fifty fathoms) is Ostrea 
tsla-galli ; and this is covered with two kinds of stony coral, which 
r ofessor Duncan refers to Sclerohelia UirteUa and a species of 
■Rcdanophyllia, The land-shells of St. Helena have been already 
^°ticed by the late Mr. G. B. Sowerby in the Appendix to Mr. 
twin’s work on Volcanic Islands, as well as by Mr. Blofeld and 
i 
