H. Woodward — On a new Silurian Star- fish. 243 



the former have simple arms, whilst those of the latter ramify into 

 many processes. 



Although the fossil under consideration most nearly approaches 

 Euryalus, it cannot be, with propriety, referred to that or any known 

 genus of OphiuridcB, recent or fossil. In Eunjalus the five arms 

 branch dichotomously from their roots with cirrhous extremities, 

 but they are not furnished with pinnse. 



The interbrachial spaces in the body-disk of Euryalus are mem- 

 branous, whilst in the fossil, as we have seen, they are protected 

 with a covering of calcareous plates more nearly resembling, in this 

 respect, the body-disk of Ophitira. 



The addition of pinnje to the arms, together with their bifurcated 

 character offers an analogy to the Grinoidece, thus aiding us in 

 filling up another gap in the chain by which the forms that existed 

 in Palgeozoic times are linked to those of our own. 



We have in this fossil presented to us a type of Palaeozoic star- 

 fishes extending its affinities towards the GomatulcB on the one hand 

 and to Ophiura and Euryalus on the other ; exemplifying what Pro- 

 fessor Owen has so happily termed " a more generalized type of 

 structure " than any at present existing in the class EcJiinodermata. 



The same writer observes : — " As we advance in our survey of the 

 organisation and metamorphoses of animals, we shall meet with 

 many examples in which the embryonic forms and conditions of 

 structure of existing species have, at former periods, been persistent 

 and common, and represented by mature and procreative species." ^ 



Having been informed that at a meeting of the Dudley and Mid- 

 land Geological and Scientific Society (held some years since) Mr. 

 J. W. Salter suggested that this specimen should be named Eucladia 

 Johnsoni, I have great pleasure in carrying his suggestion into eff"ect. 



The star-fish rests upon a slab covered with numerous small 

 Brachiopods (Bhynchonella &oreaZ^s l*),fragments of Trilobites,.Crinoids, 

 etc., presenting the appearance of having been quietly washed on 

 shore, mouth uppermost, and being unable to right itself, it had 

 been left to die, and finally to become imbedded in the superimposed 

 sediments, a fossil of rare beauty, and a happy "find" for the 

 Dudley collector. 



Dimensions of Eucladia JoTinsoni : — Diameter of pentagonal plates, 

 eight lines ; diameter of disk, two inches ; diameter of madrepori- 

 form body, two lines ; greatest length of arm preserved, 2|- inches. 

 From centre of disk, to bifurcation of arms, 1^ inches. 



[It was with no small satisfaction that, in turning, over some MSS. 

 of my late brother, Dr. S. P. Woodward, I met with an admirable 

 photograph of this fossil (taken in 1863, by the late L. P. Capewell, 

 Esq., of Dudley), bearing the following memorandum in his own 

 hand- writing : — ^' Euryalus 1 Wenlock Limestone, Dudley (Mr. 

 Henry Johnson, Mining Engineer, Dudley). Arms five, about five 

 inches long, covered with strong tubercles, central plates, five pairs, 

 madreporiform tubercle. Photographed by Mr. Capewell."] 



^ Lecture X. Echinoderma, p. 129. " Comparative Anatomy and Physiology of the 

 Invertebrata." By Prof. Owen. 1843. 



