KONGL. SV. VET. AKADEMIENS HANDLINGAR. BAND. 25. NIO 2. 27 



Béside fchese there is an undescribed speciéa from tho Wenlock Shale of Dudley and 

 Malvern, of almost hemispherical shape. 



The nomen nudum et barbaricu,ni »Pisocrinus pentalobus, W. and Sp.», which occnrs 

 in a note by Mr. C. S. Beachler *) as indicating a species found in Niagara beds at St. 

 Paul, Decatur co, ppobaMy refers to P. Gorbyi. It is, however, a little uncertain whether 

 P. Gorbyi does not inelnde two species. I have for some years been aequainted with a 

 species from the Niagara group of W. Tennessee, of which the following is a diägnosis: — 

 Dorsal Cup low; pentagorial as seen from ventral snrface, the an gles of the pentagon being 

 radial in position: the radial faeets are verv narrow, the radial processes correspondingly 

 broad, forming the concave sides of the pentagon: basals hidden in the concavity for the 

 stcin. Now this seems to agree with specimens collected by Prof. Gorby in W. Tennessee 

 and figured by Mr. Miller (oj>. eit. Pl. VT, tigs. 21, 22, 23). The type-specimens of P. 

 Gorbyi, however, which eome from Indiana, have, as Mr. Miller points ont, a more elongate 

 and conical cup; the basals also are far more visible in a side view. 



Of the other species in the above list P. ornahis and P. flagellif 'er are here regarded 

 ,is synonyms of /'. pilula. In the specimens of P. gemmiformis and P. globosus that have 

 come under my notice (for which I am indebted to the kind offices of Mr. C. S. Beachler) 

 I can see no snch diiferences as would warrant specitic distinction, and it seems probable 

 that American palaeontologists will have to consider P. globosus as a mere variety, or even 

 as a synonym, of P. gemmiformis. Further, were it not for the difference of matrix and 

 mode of fossilisation, I could not nndertake to discriminate these species from the globose 

 forms of P. pilula, while P. piriformis could not be distinguished from the more conical 

 varieties of that species. P. Benedicti again is strikingly like the ovoido-conical English 

 specimens of P. pilula, but bas perhaps rather nafrower radial faeets. P. campana differs 

 from the conical varieties of P. pilula chiefly in size; but also in the greater height of 

 the basals. 



Pisocrinus pilula. 



(Plate I, Ags. 1 — 11.) 



1858. De Koninck ; Bull. Ac. Roy. Belgique, 2 e ser., vol. IV, p. 106, Pl. II, figs. 8—11. 



1858. P. ornatus, de Koninck, op. vit. p. 107, Pl. II, figs. 12, 13. 



1873. Salter, Cat. Canib. and Sil. Foée., p. 128; Cambridge. 



1878. Axgelin, Iconographia, p. 21, Tab. IV, figs. 4, 4 a — b. (?). 



1878. P. flagellifer, Angelin, op. ät. p. 21, Tab. IV, figs. 1, l a—e. 



Emended Diagnosis. 



Shape variable; globose, ovoid or conical; in transverse section circular, sub-pentagonal 

 or slightly trilobate. (Jreatest height (from base to bottom of radial 1'acet) never more 

 than greatest width and never less tlian 2 / 3 width. Base rougbly triangulär in outline, 

 witli no plates entirely covdfed by stein. Radial articular facet wide ou exteriör of cup, 

 with straight sides sloping towards centre of cup: radial proeesses well developed, rather 



') Araer. Geol. March, 1891, p. 170. The more correct quinquelobus would admirably suit the new 

 Tennessee form. 



