442 Prof. E. Forbes on a new genus of Cretaceous Echinidse. 



have in America footprints similar in their general character to 

 those of Europe — showing the extensive range, during the epoch 

 of the new red sandstone, of the Ornithichnites. 



Although the impressions are devoid of the rows of the joints, 

 the claws, and the integuments which are sometimes found in the 

 American Ornithichnites, and which are so well shown in Prof. 

 Hitchcock^s last publication, in the American Academy's ' Trans- 

 actions,' yet still, when we consider the action to which these foot- 

 prints have been subjected, after they had impressed the soft 

 clay, viz. the force of water carrying along with it sand ; we are 

 at no loss to account for the effacing of the more minute parts of 

 the footprints. 



In order to distinguish this impression, I propose to give it, 

 from its resemblance to the footstep of a bird, the name of Ple- 

 siothornipos Binneyi. The specific appellation is in honour of my 

 friend E. W. Binney, the first geologist who brought the im- 

 pressions of Weston Point into notice. 



XXXVIII. — On Cardiaster, a new genus of Cretaceous Echinidse, 

 allied to Holaster. By Professor Edward Forbes, F.R.S. 



In the ' Outhne of the Geology of Norfolk,' by Samuel Wood- 

 ward, two fossil sea-urchins are figured which seem to have 

 escaped the notice of the authors of the ' Catalogue Raisonne 

 des Echinides.' These are the " Spatangus eoccentricus, Rose : 

 cylindrical ; groove in front deep ; tab. 1. fig. 5 ;" and "Spatangus 

 cordiformis, tab. 5. fig. 6." The former is omitted in Morris's 

 ' Catalogue of British Fossils/ the latter is referred with a query 

 to the genus Holaster. 



I have lately had ample opportunities of examining several 

 specimens of each of these rare and curious fossils, and have 

 satisfied myself that they belong to a genus not yet characterized, 

 nearly allied to Holaster and Ananclujtes, having the same ar- 

 rangements of ambulacra, genital disk and mouth, but eminently 

 distinguished from those genera (and in this respect linking them 

 more closely with the Spatangaceoe) in having a distinct peri- 

 petal fasciole. Remarkably diflPerent as the two species cited 

 appear, they unquestionably belong to one genus ; this I pro- 

 pose to name and define as follows : — 



Cardiaster, Forbes. 



[Echinidce. Fam. Spatangacea. Sect. Ananchytidce.) 



Test cordiform. Ambulacra converging on the summit of the 

 back without meeting, simple and not petaloid, the anterior am- 

 bulacrum lodged in a deep and steep- sided furrow. Arrange- 



