278 BULLETIN 88, UNITED STATES NATIONAL MUSEUM. 



vated adjacent or adradial plate. The adradial plates form a pair, 

 which, meet in the interradius. The arrangement is similar to that 

 which occurs in the genus EutTiemon, to be next described; in the 

 latter, however, the plates are not overlapping, but tesselated. 

 The overlapping of the plates is less on the ventral than on the 

 dorsal side, a difference which is probably due to the less amount 

 of displacement suffered by the ventral plates; and this, again, is 

 explicable on the assumption that the ventral surface was flatter 

 than the dorsal. 



" The arms. The arms of this species do not exhibit that marked 

 increase in size, as their position in the series becomes more distal, 

 which is characteristic of Eucladia johnsoni. Their average length 

 is 25 mm. Near their tapering extremities the arms present on both 

 dorsal and ventral surface three plates, two of which are lateral 

 and one median, recalling the characteristic plating of an Ophiuroid 

 arm; but nearer the origin the number of conspicuous plates on 

 either surface is increased to four or even more, and smaller supple- 

 mental plates are inserted between them in a manner precisely 

 similar to that already described hi the case of Eucladia johnsoni. 

 The larger plates, swollen at first and becoming mucronate finally, 

 are produced into a short awn-like termination. 



"A search, which proved unsuccessful, was made for some trace 

 of vertebral ossicles; had these structures been present originally, 

 they must either have been very small or some traces would still 

 be discernible. In Lapworihura, which occurs in the same rocks, 

 the vertebral ossicles are the most obvious elements in the brachial 

 skeleton. 



"The distinction of Eucladia woodwardi from E. johnsoni rests 

 on the smaller number of arms possessed by the former and the 

 closer approach of these to equality in dimensions. The speci- 

 men selected as the 'type' is exhibited in the Oxford University 

 Museum, and bears a label stating where its description may be 

 found." 



Formation and locality. In the Lower Ludlow, Leintwardine, 

 England. 



EUCLADIA (?) BEECHERI, new species. 

 Plate 38, fig. 1. 



As this problematic fossil is of considerable interest, it is thought 

 best to make it known in this work, even though the preservation 

 is not good. The general characters are easily seen in the specimen, 

 however, and much better than can be shown by photography, but 

 in detail very little can be made out. The fossil lies in a dense 

 dark limestone beneath the surface of a parting between two beds 



