262 Prof. Be Konmck. — New British Echinoderms. 



name of H. Clio, had remained the only representatives of the genus, 



of which no trace had been discovered, either in the SUurian strata, 

 so rich in crinoids, or in the Carboniferous series, where these fossils 

 are also abundant. 



The discovery of a Carboniferous Haplocrinus offers a certain 

 interest; it is to Mr. Parker that it is due. It is to his kindness that 

 I owe the only specimen found by him in the Carboniferous Lime- 

 stone of Bolland in Lancashire, amongst a considerable number of 

 other fossils of less importance. 



Haplocrinus granatum, de Kon. Calyx small, ventral part sub- 

 globular, hemispherical, buccal part or dome depressed, pyramidal, 

 with a pentagonal base. Surface smooth to the naked eye, but 

 when examined with the magnifying glass, one discovers some 

 slight irregular rugosities. The base is relatively little elevated, 

 and the part by which it has been articulated to the stalk is rather 

 deeply hollowed, and is surrounded by a small circular burr. Its 

 outline is irregular, two of the sides of the pentagon which form its 

 projection are smaller than the three others, which are of about 

 equal dimensions. 



The three sub-radial pieces are very much broader than long; 

 they are pentagonal, but the angle made by the remainder of the 

 borders attached to the basal pieces is very obtuse. The fine 

 radial pieces are relatively very large, and form alone the greatest 

 part of the calyx ; their surface is slightly rugose, their form is 

 pentagonal, and the superior border is undulated. On the median 

 part of this border, to which the arms must have been articulated, 

 one can detect a slight swelling, in which is hollowed out a small 

 furrow, which continues up to the summit of the dome or vault. 



The inter-radial pieces are five in number, and alternate with the 

 radial plates. All are subtriangular, and very nearly of the same 

 form and size — their lateral borders being bevelled, form, by their 

 juxtaposition, the five radiating furrows seen on the vault, and to 

 which I have already referred. Of the form and disposition of the 

 jointed arms, I am unable to speak, as they are entirely wanting. 



Compared with the species from the Eifel, this one can easily be 

 distinguished by its general form, which is less globular, by the 

 nearly complete absence of ornamentation on its surface, by the 

 greater elevation of its dome, and above all by the peculiar form of 

 the furrows which are scooped out upon it. It approaches more 

 nearly to the H. Clio of Hall. 



EXPLANATION OF PLATE VII. 



Fig. 1. Palcechinus spheericus, Scouler (nat. size), from the Carboniferous Limestone 

 of Kirkby-Stephen, in "Westmoreland. The original in the collection of 

 Edward Wood, Esq , F.G.S., of Richmond, Yorkshire. 



Fig. 2. Plaeocystites Forbesianus, de Kon., from the collection of John Gray, Esq. 

 (now in the British Museum). Specimen of the natural size seen from 

 the anterior side, a, anal aperture ; b, ovarian orifice. 



Fig. 3. The same specimen seen from the posterior side. 



Fig. 4. „ „ „ base. 



Fig. 5. Transverse section, taken upon a line passing through the body near the 

 anal aperture. 



