418 Mr. II. J. Carter on remarkahle Forms of 



sufficient remains in the interior, as determined by the section 

 of another but inferior specimen, registered 22. 8. 76. 5, to 

 show what the form was. 



Palytlioa seyiegainhiensiSj n. sp. 

 (PL XVI. fig. 2, a-c, and fig. 3, a, h.) 



Polypary consisting of four or more stout clumsy arms, 

 bent downwards asteroidly from an arched summit, under 

 which and on one side is an aperture representing that of the 

 shell on which the Palytlioa had grown (PI. XVI. figs. 2 and 

 3). Composition siliceo- arenaceous. Structure subfirm, gritty. 

 Colour light brown. Arm irregular in shape, about 7-12ths 

 of an inch thick in its most cylindrical part, simply rounded 

 at the end (fig. 2, 5), or expanded and flattened (fig. 3, h). 

 Aperture elliptical, about 8-12ths by 3-12ths of an inch in 

 its greatest diameters (fig. 3, a). Surface uniformly covered 

 with a great number of papilliform eminences (fig. 2, a), 

 more or less in juxtaposition, slightly raised above the com- 

 mon level of the poly))ary, circular, and about 3-24ths of an 

 inch in diameter, with a 12-})licated aperture in the centre 

 more or less open, leading to a cavity beneath about the same 

 in depth sunk into the polypary, and presenting the remains 

 of at least twelve mesenteric lamella?; thus the cavity bears 

 the proportion of 3 to 14-24ths of an inch when compared 

 with the thickness of the cylindrical part of the arm, which 

 otherwise is composed of pure sand (fig. 2, c). Polyp too 

 much desiccated for description. Size of specimen about 

 2| inches from tip to tip of the longest arms ; height of the 

 summit of the arch outside about 2^ inches, inside about 

 I inch. 



Hah. Marine. 



hoc. Coast of Senegambia, West Africa. 



Ohs. Although the branched form of this polypary &c. 

 much resembles that of an Alcyonium^ yet the arenaceous 

 composition and general appearance is more like that of a 

 Palytlioa, to which " subfamily " it must be relegated on 

 accouiit of the greater number of mesenteric lamella, which, 

 according to Milne-Edwards, " reste toujours a huit chez les 

 Alcyonnaires " (^Zoophytes: Coralliaires,' vol. i. p. 221). From 

 the polyps being only sunk into the polypary so much as to 

 be a little above the general surface, or rather, perhaps, from 

 the latter having risen to this height, it evidently belongs to 

 Milne-Edwards's division "AAA" {op. cit. vol. i. p. 305), 

 although a hranched form is not mentioned. The exjninded 

 and flattened ends of the arms of the illustrated specimen 

 (fig. 3, h)j for there are two very much alike, seem to indicate 



