366 
Mr. P. W. Bassett-Smith on 
Tizard Bank, 7 fath. On block of coral-rock in associa- 
tion with specimens of Madrepora , Favia ) &c. 
Genus Pocillopora, Lam. 
The examples of this species are fairly numerous ; with 
one exception, which was found in 26 fathoms, they have all 
been obtained in depths under 10 fathoms. The specific deter- 
mination of these forms is extremely difficult; the definitions 
given by Lamarck, Edwards and Haime, and other older 
authors are so general that it is impossible to know what they 
include ; and, on the other hand, the variations in the cha- 
racters of the corallites appear to be so slight in the different 
forms that they may almost be considered as forming a con- 
tinuous series separated only by slight modifications in their 
mode of growth. In the absence of authenticated specimens 
of known species the list given below can only be regarded 
as provisional. 
Pocillopora elongata ) Dana. 
1848. Pocillopora elongata , Dana, Zoophytes, p. 531, pi. 50. fig. 4. 
Three specimens from depths of 2-6f fath. 
Tizard Bank. 
Pocillopora verrucosa , Ell. & Sol., sp. 
1786. Madrepora verrucosa , Ell. & Sol. Nat. Hist. Zooph. p. 172. 
1836. Pocillopora verrucosa , Lam. Hist, des Anim. sans Vertbebr. 6d. 2, 
t. ii. p. 443. 
There are several examples of this species, which appears 
to have flourished all over the reef. Depth 1-10 fathoms. 
Tizard and Macclesfield Banks. 
Pocillopora brevicornis , Lam. 
1836. Pocillopora brevicornis , Lam. Hist, des Anim. sans Vertebr. ed. 2, 
t. ii. p. 443. 
1848. Pocillopora brevicornis , Dana, Zooph. p. 526, pi. xlix. fig. 8. 
Several examples from depths §-l fath. ; one specimen 
6^ fath. 
Tizard Bank. 
Pocillopora } sp. 
A single specimen, which in its mode of growth resembles 
P. brevicornis ; but the branches are considerably thicker and 
the corallites somewhat larger. 
Garvan Reef, Tizard Bank, 2 fath. 
