310 Mr. H. J. Carter’s Contributions to our 
shape of the specimen also, renders this species very easy of 
determination. ‘There would be nothing extraordinary in the 
cribriform incrustation, as it is common among the Bibulida 
and Hercinida, were it not that it is so uniform in structure, 
smooth, and continuous, on account of the entire absence of 
any projection of the dermal fibre to render the surface poly- 
gonally divided, as in these families generally ; but the wool- 
like character of the fibre, owing to its being so small and 
uniform in size, 7s peculiar. ‘The specimen, which is very 
striking, is in the Bowerbank general collection at the British 
Museum. 
Order V. ECHINONEMATA. 
Family 1. Ecry onIDA. 
Char. “ Echinated with proper spicules on the fibre” 
(‘ Annals,’ /. c. p. 133). 
Ectyon mauritianus, n. sp. (Pl. XII. fig. 3, a, 6.) 
Entire form not seen. General and microscopic characters 
the same as those of Hctyon sparsus (‘ Annals,’ 1871, vol. vii. 
p- 270), with the exception of the spicule, which is nearly 
twice the size and still more beautifully ornamented, as may 
be seen by the illustration (Pl. XII. fig. 3, a), which is drawn 
upon the same scale as that of HZ. sparsus for comparison (op. 
et loc. cit. pl. xvi. fig. 8, a, 6). It is about 52 by 4-6000ths 
inch in size, not including the projections of the spines late- 
rally, each of which amounts to 1-6000th inch on each side, 
which gives a total diameter of 6-6000ths, for its greatest 
dimensions. ‘The spines, instead of being circular and based 
on the surface of the spicule, as in L. sparsus, are compressed 
laterally and raised on an angular ridge or inflation, whereby 
the spicule presents a moniliform appearance, that is, a series 
of constrictions, which renders it so much more beautiful than 
that of L. sparsus, as before stated. 
Hab. Marine. 
Loc. Mauritius. 
Obs. This specimen, with many others, was collected at the 
Mauritius by Col. Pike, then U.-S8. Consul there, and for- 
warded to me by the late Dr. Dickie, F.R.S., in the month 
of November 1872*. It is not more than 2 inches in dia- 
* IT learnt from Mr. J.S8. Tyerman in October 1881 that, when he 
was living at Liverpool, the collection was sent to him first, and that he 
sent it on to Dr. Dickie, the latter to Dr. Bowerbank, who, after a 
