Eenry 'Woodward — On a New Devonian Starfish, 9 



The specimens are preserved as casts of the calcareous skeleton, 

 from which all the integument has been removed. We cannot there- 

 fore hope to discover the madreporiform tubercle, or those delicate 

 tufts of spines with which the dorsal surface of the disk and arms 

 of most of the Solasterise are invested. 



Each arm is composed of from fifteen to twenty pairs of small and 

 somewhat ovate plates, which unite along the centre and form the 

 roof of the radiating grooves which one sees on the ventral side of 

 all existing Starfishes, and in which those curious and delicate 

 tubular extensile organs, the suckers (which serve the office of feet, 

 and by means of which the animals can walk about with great 

 facility), are ranged. 



In the Solasterise there are only two rows of these suckers in each 

 avenue, whilst in the Asterige there are four. 



The casts of these plates, with their slender mesial connecting 

 ridge, resemble one of the delicate pinnules of the leaf of a Lastrcsa, 

 or, when viewed as a whole, one is reminded of the little plants of 

 Aspleniiim tricJiomanes, common on our country walls. 



The disk, unfortunately, is not preserved in either of the specimens 

 sent to me, but it must have measured 10 mm. in breadth. The 

 arms are 17 mm. in length, and near their junction with the body 

 are 5 mm. broad ; the greatest breadth of the entire Starfish is about 

 45 mm. 



Writing of Lepidaster Grayi, Prof. Edward Forbes observes : — 



" This fossil bears at first sight a strong resemblance to a Starfish of the genus 

 Solaster, but in reality it possesses characters so peculiar as without doubt to stamp it 

 as a separate generic type, and even to render doubtful its position among true Star- 

 fishes, and to raise the question whether it be not a connecting link between that 

 order of Echinoderms and Crinoids. 



The disk is very little more than two inches in diameter. It is so injured that its 

 elements cannot clearly be made out, but it appears to have had a framework of 

 closely set polygonal ossicula. The rays are arranged around it equidistant from 

 each other, like so many spokes of a wheel. Their average length is one inch and 

 one-twelfth, and their breadth towards the base four-twelfths. They are all regularly 

 lanceolate. Their under-surfaces are exposed on the slab, and are composed of thick 

 transversely oblong plates, slightly overlapping each other in a scale-like fashion, and 

 ranged mfour longitudinal rows, two on each side of a central or ambulacral groove, 

 which is itself toward the extremity in some instances partially filled up by small 

 polygonal intervening plates. Of the two rows of border plates on each side of the 

 groove, the inner series is formed of oblong obscurely hexagonal ones, with traces of 

 punctations and grooves on their surfaces as if for spines. The ray that is most 

 perfect exhibits twenty-five plates in each row. The outer series consists of sub- 

 orbicular or obscurely polygonal plates, which, like the inner ones, are slightly convex 

 on their surfaces. The upper surface of the ray, and probably of the body, was 

 composed of numerous small polygonal, nearly flat ossicula, closely set and of various 

 sizes." (1850, Mem. Geol. Surv., Decade iii. pi. i. p. 1.) 



In Helianthaster Hhenanm (Eoemer) the disk is 30 mm. broad, 

 and the arms are double that in length. 



The arms themselves are bordered on each side by small knobs or 

 ossiculee, with traces of two finer lines of obliquely-placed and 

 smaller plates along the middle of each arm, bordering the ambulacral 

 groove ; whilst a small oval plate marks the base of and separates 

 each arm where it joins the body. There are also remains of spines 

 on the borders of some of the arms. The disk is not preserved, and 



