98 Mr. E. Parfitt on a new Species of Cellepora. 



themselves with body, tail, and antennae all in one line, 

 instead of assuming the angular prancing attitude of their 

 congeners. 



A fifth specimen differs from the other four in having the 

 head wider and the fourth segment of the body much narrower, 

 and in being without any dark markings on the skin. This 

 is probably the male. 



EXPLANATION OF PLATE III. A. figs. 1-3 a. 



Fig. 1. Cymodocea tuberculosa ; 1 a, underside of tail-piece ; 1 b, leg. 



Fig. 2. Arcturus coruiger. 



Fig. 3. Arcturus lineatus ; 3 a, one of the upper antennae. 



XIII. — On a new Species of Cellepora. 

 By Edward Parfitt, Esq. 

 [Plate III. B. figs. 1-6.] 

 To the Editors of the Annals and Magazine of Natural History. 



Gentlemen, 



I beg to introduce to you a new species of Cellepora dis- 

 covered by me at Exmouth in the autumn of 1872, a descrip- 

 tion and figures of which I enclose. I have named it Cellepora 

 hemispha^rtca, from the cells forming little hemispherical 

 masses. It appears to be perfectly distinct from any thing I 

 can find, either amongst the fossil or recent species. 



I am, Gentlemen, 

 Yours obediently, 

 Exeter, June 11, 1873. EDWARD PARFITT. 



Cellepora hemisplimrica, n. sp. 



Cells heaped together irregularly into, generally speaking, 

 hemispherical masses ; mouth simple, elliptical ; cells variously 

 formed, but generally ovate, white, shining, and thickly per- 

 forated ; sometimes they are very much inflated, and in other 

 specimens they are more or less depressed ; many of the cells 

 are mouthless, or open into other contiguous cells. Avicularium 

 or vibraculum very rarely developed : I have only seen one ; 

 and this, I think, was abnormal, as it was in the back of the 

 cell. Ovicell ? Animal ? 



The minute masses of cells are attached by the somewhat 

 flattened underside to the branches of Sertularia abietiaa : the 

 edges of the mass slightly curve, so as to fix themselves firmly 

 to the branch ; they measure generally about one 25 di of an 

 inch in diameter. 



