2/6 MR.W. S. KENT ON NEW MADRKTORES. [Apr. 4, 



This species differs from Acanthocyathus grayi (M.-Edw.), the 

 only recorded existing form, in the straight instead of curved contour 

 of its corallum, in its prominent costae bearing spinous processes on 

 others besides the two lateral primary ones, and in its more par- 

 ticularly exsert primary septa. 



Its costal peculiarities seem to demonstrate its being more closely 

 allied to A. hastingsce (M.-Edw.), a species occurring as a fossil in 

 the Miocene deposits of Malta. 



Figs. 1 b and 1 c of Plate XXIII. illustrate various stages of deve- 

 lopment of A. spiniger; the extra spines present in fig. 1 appear to 

 be characteristic of the adult condition. Though all the specimens 

 examined are free, each exhibits traces of an early attachment. 



Flabellum matricidum, n. sp. (Plate XXIII. figs. 2, 2 a, b, c.) 



Corallum elongate, almost cylindrical, attached by its base. 

 Calicular fossa circular, very deep. Theca exceedingly slender, in- 

 vested by a complete epitheca. Septal cycles four in number, the 

 last cvcle incomplete. Primary and secondary septa scarcely exsert ; 

 lateral surfaces of septa granulate, their inner edge delicately flexuous 

 above, thickened inferiorly, and becoming lost in the trabecular 

 elements of the rudimentary columella. Costae even, distinct 

 throughout. 



Hab. Japan. B.M. 



The mode of increase in this species is exceedingly remarkable, 

 resulting from internal gemmation at the expense of the parent 

 calyx in the following manner : — The adult condition being arrived 

 at, a bud makes its appearance immediately within the margin of the 

 calyx, and, rapidly increasing in size, becomes confined by the oppo- 

 site wall of the parent ; this, owing to its tenuity and the pressure 

 exerted upon it, fractures and falls to pieces, the young bud still 

 remaining attached to the portion from which it originated. 



Family Oculinid.e. 



Amphihelia infundibulifera, nobis. (Plate XXIV. figs. 4, 

 4 a, b.) 



O. ramosissima, subfiabellata ; ramvlis ultimis minimis Jlexuosis ; 

 stellis infundibuliformibus, interne striatis ; margine crenulato. 



Oculina infundibulifera, Lamarck, Hist, des Anim. sans Verteb. 

 p. 286, 1816. 



AUopora (Stylaster) infundibulifera, M.-Edw. Hist, des Corall. 

 t. ii. p. 131, 1857. 



Specimens in the British Museum, collected at Formosa by 

 Consul Swinhoe, are evidently identical with the species described as 

 above by Lamarck ; but the entire absence of a columella and the 

 unequal development of the septal cycles preclude its being referred 

 to the group of the Stylasteraceae, as proposed by Milne-Edward9. 

 These characters, when added to the alternate distal mode of 

 increase of the calices, and the remarkable development of the basal 



