230 Messrs. E. Etlieridge, Jun. ,«??<:/ P. 11. Carpenter on 



from ■wLi'cli it differs in size, in the elevated nature of its 

 interradii, and in its greater number of hydrospiral slits. As 

 regards form, PZi. T^erwf?«7/ represents one extreme moditica- 

 tion of the genus, and Ph. caryoplnjUatum another. 



Loc. and Horizon. Asturias, Spain 5 Devonian (Mus. Nat. 

 History) . 



PJuvnoschisnia ArcMad, sp. nov, 



Sp. char. Calyx clavate, becoming more pentalobate with 

 age. Tlie angles of the pentagon correspond to the distal 

 ends of the ambulacra ; and its sides are concave, not straight. 

 Base long and sharp ; oro-anal surface truncate. Basal 

 plates very long and slender, longer than the radials, expand- 

 ing very gradually into a small cup, the surfaces ornamented 

 with concentric stria? having two different directions. Hadial 

 plates small, lobate about the lips, projecting somewhat up- 

 ward, and obliquely truncate on their upper margins ; those 

 of the anal interradius are a little flattened. Surface somewhat 

 angular in the middle line from the lips down to the basi- 

 radial suture. Sinuses short, having a radial angle of about 

 130°, and somewhat petaloid. Orals confined to the immediate 

 neighbourhood of the mouth. Ambulacra short, a little peta- 

 loid ; lancet-plate lanceolate, narrow, deeply triangular in 

 section ; side plates few, six to eight or nine, oblong ,• outer 

 side plates triangular^ very small. Hydrospire-slits six on 

 each side, the sixth partially covered by the lancet-plate, two 

 only being entirely exposed when the side plates are in 

 position, Hydrospires in the form of long, pendent, slender 

 sacs. Mouth small ; anus roundly triangular. Surface of 

 plates ornamented with concentric striffi. 



Ohs. Ph. Archiaci does not possess the elevated inter- 

 radial spaces of Ph. Verneutli, and is thereby distinguished 

 from it, apart from their differences in other characters. The 

 outline of the calyx generally, the form of the anal interradius, 

 and the general features of the ambulacra and hydrospire- 

 slits separate it from Ph. acuium. It is also unlike Ph. caryo- 

 pliyllaium, but may be said to be a transitional form between 

 the two former species and the latter. The ornamentation of 

 the basal plates is quite similar to that of a species of Pentre- 

 mitidea [P. lusiianica) , and might lead to a confusion of tlie 

 two species should the generic characters not be properly 

 attended to. 



Genus CODASTER, M^Coy, 1849. 

 Cadaster, M'Coy, Ann. & Mag. Isat. Hist. 1849, iii. p. 250. 



