254 FOREIGN OOLITIC ACROSALENIAS. 



towards the disc and peristome ; miliary zone moderate in width, and composed of four 

 rows of granules ; mouth opening large, peristome decagonal ; discal opening large. 



Dimensions. — Height, eight tenths of an inch ; transverse diameter, one inch and four 

 tenths. 



Formation. — Cornbrash (Bathonien) Marquise. 



Collections. — British Museum, Neuchatel Museum, M. Bouchard, M. Michelin, my 

 cabinet. M. Desor states that this species is often ticketed in Conti- 

 nental collections by mistake, Hemicidaris Luciensis> d'Orbigny ; the 

 latter is altogether a different urchin. 



AcROSALENiA GRANULATA, Merian. Syn. Hemicidaris granulata, Merian, in Agassiz's 



Catalogue raisonne, Annal. Sc. Naturelles, 

 tome vi, p. 339, 3"^ serie. 



A small, depressed species. The ambulacral tubercles are so small that they resemble 

 miUary granules ; the tubercles of the inter-ambulacral areas are disposed at some 

 distance apart. 



Formation. — " Grande Oolite (Vesulien) de Gensingen (Argovie), avec les Disaster 

 analis, Holectypus depressus" &c. Desor. 



Collections. — Museum Bale, Collection M. Msesch. Very rare. 



AcROSALENiA ELEGANS, Dcsor. Syuopsis des Eebinides Fossiles, p. 143. 



This species, according to M. Desor, resembles the preceding. It is larger, but has 

 small mouth opening, and the ambulacral tubercles are excessively small. 



Formation. — " Grande Oolite (Vesulien) du Romberg (Argovie), avec la precedente. 



" Co//ec^eo;?.~-M8esch." Desor. 



