52 



On Pentacrini in Great Oolite near Bash. 



Those who think such name-giving unsafe and worse than need- 

 less will perhaps excuse me when they learn that in the general 

 collection of the Basle Museum there are similar fragments 

 labelled ^'■Peritacr. tuherculatusy Desor, Terrain a chailles, Kl. 

 Basel," and that to this M. de Loriol lias added in MS.: "Ce 

 Pentacrinus me parait app. a une espbce nouvelle tres-voisine 

 du P. siilsulcatus, Miinster, du Lias : ce dernier n'a pas de creux 

 sur les sutures. Corame il n'y a ni localite ni niveau indiqu^, 

 je m'abstiens de la decrire.'" The stems are pentagonal and 

 basaltiform ; the stem-joints equal one another in height and 

 diameter. The angles are well marked, but there is no re- 

 entrant angle. The sutures are depressed on the lateral faces, 

 but not on the angles ; thus there is a ridge on each face of 

 the joint between the angles. This gives the stem its charac- 

 teristic scalariform appearance. The surface is otherwise 

 smooth. The crenulations, which form a rosette on the arti- 

 cular surface, are only visible on the exterior at the angles ; 

 this is owing to tlie depression of (he suture on the intervening 

 face. The diameter is slight, varying from '9 to 2*5 milli- 

 metres in different specimens. 



It should perhaps be noted that M. de Loriol has figured 

 as Pentacr. crista-galli^ Quenst., some small stem-fragments 

 from the lower beds (Bajocien) of Muttenz, in the collection 

 of M. E. Greppin ■^. These figures bear some resemblance to 

 the present species. P. Bastlece may be descended from P. 

 crista-galliy but it is certainly not identical. 



Fio-. 1. 



Fij?. 2. 



Fig. 1. — rentacrinus Kicoleti, var. minimns, from Great Oolite of Mut- 

 teuz, near Basle ; in British Museum [E. 5505] ; X 4 diam. a, 

 side view ; b, articular surface. 



Fig. 2. — Fentacrinus Basilea, GreatOulite, Muttenz ; Brit. Mus. [E. 5500]; 

 X 6 diam. n, articuLxi' surface, rather worn ; b, side view, the 

 crenulation of the suture at the auple has not been copied well 

 by the engraving process. 



* Monoo-r. des Crinoidea fossiles de la Suisse, pi. xv. figs. 29 aiid 30, 

 vide p. loG°; in Mem. Soc. pal. Suisse, vol. vi. (Basle and Geneva, 1879). 



