18 FISHES AND FISHERIES OF THE IRISH SEA. 
cent., and the calcium carbonate from 40 to 80 per cent. In all the neritic deposits there are 
in the residue small quantities of calcium phosphate, of iron, and of alumina. 
In some of these deposits the calcareous matter is formed almost entirely of 
Lithothamnion. Amongst the Nullipores from our neritic deposits Professor Harvey Gibson 
has identified the following species :—Lzthothamnion polymorphum, L. calcareum, L. agariciforme, 
L. fasciculatum, the variety fruticulosum, and Lithophyllum lenormandi. 
One of these neritic deposits (A) has its calcareous matter formed by a large number of 
animals, belonging to various groups, in addition to nullipores. One sample (measuring 
7 qts. 1} pts., and weighing, when dry, 17 lbs. 3} ozs.) which was gone over carefully for the 
purpose of identifying the constituent particles contains more or less fragmentary remains of at 
least the following 99 species, all of them forms that leave calcareous remains :— 
NULLIPORES : 
Lithothamnion fasciculatum 
L, calcareum 
Lithophyllum lenormandi 
ECHINODERMATA : 
Echinus sphera 
Echinocyamus pusillus 
Echinocardium cordatuim 
VERMES : 
Serpula, sp. 
Spirorbis, sp. 
POLYZOA : 
Cellaria fistulosa 
Cellepora avicularts 
C. dichotoma 
C. pumicosa 
Ldmonea serpens 
Microporella ciliata 
M. malusit 
M. violacea 
Schisotheca fissa 
S. divisa 
Mastigophora hyndmanni 
M. dutertrez 
Mucronella peachit 
M. vartolosa 
M. ventricosa 
M. coccinea 
Do., var. mamillata 
Schisoporella auriculata 
S. linearis 
S. unicornis 
S. simplex 
S. vulgaris 
S. discotdea 
S. cristata 
Membranipora catenularia 
M. solidula 
M. pilosa 
M, nodulosa 
M. discreta 
M. aurita 
MM. craticula 
M. flemingit 
fHippothoa distans 
Cribrilina annulata 
C. punctata 
C. gattye 
Crista aculeata 
tea recta 
Amathia lendigera 
Porella concinna 
Do., var. belli 
P. minuta 
Cribrilina radiata 
Phylactella collaris 
P. labrosum 
Micropora cortacea 
Chorizopora brongniartit 
Diastopora patina 
D. obelia 
D. suborbicularis 
Stomatopora johnstont 
S. tncurvata 
Lepralia foliacea 
L. pertusa 
Lagentpora socials 
Smittia trisptnosa 
S. reticulata 
Lichenopora hispida 
