from the Island of Malta. 1 25 



the central mouth-opening and the form of the interambulacrum 

 induce us to think that it is only a gigantic variety of E. Richardif 

 and not E. Kleinii, as supposed by Desmoulins. The identity oif 

 this species with Klein's Scutum ovatum Issyaviense may or may 

 not be correct, as the figures of fossils in that work are not in 

 every case to be depended on. 



Affinities and differences. — E. Richardi has some resemblance 

 to E. Kleiniij but the narrow ambulacral areas, the flattened 

 sides, and produced caudate interambulacrum in E. Richardi 

 afford points of distinction by which these allied forms may be 

 readily distinguished from each other. In E. Kleinii the base is 

 more concave, the mouth nearer the anterior border, and with 

 larger oral lobes than in E. Richardi. The dorsal surface presents 

 other points of difference : in E. Kleinii the posterior half of the 

 test is the most elevated, whilst in E. Richardi it slopes rather 

 abruptly downwards from the vertex to the truncated posterior 

 border. 



Locality and stratigraphical range. — It was collected from bed 

 No. 2, at Malta; the specimen before us is the only one in 

 Earl Ducie's cabinet. The Geological Museum in Jermyn Street 

 possesses an interesting series of this form, which are all from 

 the same island. Grateloup found the large variety at Dax, in 

 the "faluns bleus de Narrosse,'' and adds that it is found like- 

 wise at Paris, Montpellier ?, Bordeaux, and the Vicentin : Des- 

 moulins adds St.Paul-trois-Ch^teaux (Drome) as another locality. 



Genus Conoclypus (Agassiz, 1839). 



Test thick, hemispherical or oval, and always much elevated ; 

 ambulacral areas above long, wide, converging at the summit, a 

 little contracted below ; mouth median, symmetrical, pentagonal, 

 and surrounded by five large lobes ; base flat, basal portion of 

 the ambulacra with poriferous zones around the mouth-opening ; 

 anus inframarginal, sometimes transversely oblong. The spe- 

 cies are all fossil, and belong mostly to the tertiary rocks : one 

 is found in the Maestricht chalk. This genus is nearly allied to 

 Echinolampas. The character upon which M. Agassiz relied as 

 diagnostic between Conoclypus and that genus, the direction of 

 the anus, which is stated* to be elongated in the antero-posterior 

 diameter in Conoclypus, and in the transverse diameter in Echi- 

 nolampas, does not hold good in all the species. 



Conoclypus plagiosomus, Agassiz. 



Syn. Conocyplus plagiosomusy Agassiz and Desor, Cat. rais., Ann. 

 So. Nat. 3rd series, tom. vii. p. 168. 



Test thick, large, highly convex ; border acute ; outline round, 

 * Ann. Sc. Nat. tom. vii. p. 167. 



