308 
SELACHII, 
1868. Strophodus rcitisbonensis, C. W. Ton Giimbel, Geogn. Beschreib. 
Ostbav. Grenzgeb. (Geogn. Beschreib. Konigr. Bay., pt. ii.), p. 762, 
woodc. 1 
1869. Strophodus medius, B. Owen, Geol. Mag. yol. yi. p. 193, pi. yii. 
1875. Aster acanthus ornatissimus, K. Fricke, Palfeontogr. yol. xxii. 
p. 387, pi. xxii. fig. 4. 
1875. Asteracanthus preussi, K. Fricke, tom. cit. p. 388, pi. xxii. fig. 1. 
1875. Strophodus reticulatus , K. Fricke, tom. cit. p. 391, pi. xxi. fig. 16. 
1888. Asteracanthus ornatissimus , yar. Jlettonensis, A. S. Woodward, 
Ann. Mag. Nat. Hist. [6] yol. ii. p. 336, pi. xii. 
Type. Dorsal fin-spine; Paris Museum of Natural History. 
The type species, of very large size, the exserted portion of the 
dorsal fin-spine sometimes attaining a length of 0-48. 
Dorsal fin-spines robust, ornamented by relatively large, rounded 
or elongated, stellate tubercles, of unequal size, generally arranged 
in longitudinal series, sometimes very irregular, rarely in part 
fused into short ridges ; anterior face rounded, sometimes keeled; 
posterior face raised into a median longitudinal ridge, with two 
series of large denticles. 
Crowns of the small hindermost teeth, and those of series m., 
iv. gently rounded, coarsely reticulated, without longitudinal keel, 
hut the most prominent superficial markings often becoming in part 
nearly parallel and transverse • teeth of series i., ii. considerably 
elevated, prominently keeled in the (Flower) jaw, less so in the 
opposite, the superficial ornament partly reticulate, but the principal 
markings more or less transverse and radiating or parallel. 
That the dentition named Strophodus reticulatus by Agassiz 
pertains to this species, is proved by specimens from the Oxford 
Clay, described by the present writer, loc. cit .; and the nearly 
complete dentition of one jaw is made known by the so-called 
S. medius. 
Form.Sf Loc. Lower Oolite: Normandy. Middle Oolite: S.England. 
Ipper Oolite: 8. England. N. France, W. Switzerland, and N. 
and S.W. Germany. 
(i.) Dorsal Fin-spines . 
P. 588. Type specimen of A. pcipillosus described by Egerton, loc. 
cit .: Great Oolite, Caen, Normandy. Egerton Coll. 
32731—2. Greater portion of a smaller spine, with very large 
posterior denticles, and the tubercular ornament finer than 
in the last; also a portion of a spine of similar size, with 
relatively larger tubercles ; Caen. Tesson Coll. 
1 This “ species ” is described as obtained from the Greensand; but Dr. K A. 
von Zittel informs the present writer that it was most probably obtained from 
the underlying Jurassic rocks. 
