204 DEVONIAN FAUNA. 



remarking that it perhaps differs generically from another species which he places 

 beside it, seems very nearly akin to the present form, but its subsidiary tubercles 

 are very much larger and more regularly placed. 



2. CLASS ASTEROIDEA, Grey, 1840. 

 1. OKDER ENCRINASTERI^], Bronn, 1860. 

 1. Genus PALJIASTEK, Hall, 1852. 



1. PAL.EASTER LONGIMANDS, Whidborne. Plate XXVI, figs. 1 4 ; and Plate XXIX, 



fig. 3. 



1896. PAL^ASTER LONGIMANUS, Whidborne. Proc. Geol. As*oc., vol. xiv, p. 376. 



Description. Upper surface of body of medium size, convex, without any 

 expanded disc, and with five very long slightly tapering arms. (Madriporiform 

 tubercle unobserved.) Surface covered with polygonal or subquadrate tesselated 

 plates, each bearing a large rounded central tubercle. Plates arranged in from 

 seven to five longitudinal rows on the arms, the central row being the largest, 

 and the lateral rows smaller, the plates gradually diminishing from the centre. 



Under surface having narrow transverse ambulacral plates with large grooves, 

 bounded by a row of large transverse adambulacral plates which alternate with a 

 row of smaller marginal plates. 



Oral plates small, triangular. Arm-plates in more than fifty transverse rings. 



Size. Length of a single arm about 20 mm. ; hence the animal, if regularly 

 expanded, would measure about 35 mm. 



Localities. In the Museum of Practical Geology are four specimens labelled 

 "Park, near Braunton," " Braunton Down," "Baggy Point," and "North 

 Devon." In the Woodwardian Museum are two specimens from Top Orchard ; 

 in the Porter Collection one from Pilton ; and in my Collection one from Top 

 Orchard. 



Remarks. I have repeatedly searched these specimens, which are all casts, 

 for a madriporiform body, but, probably from their state of preservation, have 

 not been able to discover anything resembling one. The external skeleton of the 

 arms seems generally to consist of a large central plate, having on each side a 

 smaller proximate plate, three very small lateral plates, a larger marginal plate, 

 and a still larger transverse adambulacral plate, so that the ring is composed 

 normally of thirteen rows, but occasionally an additional row seems to be present. 

 The shape of the plates of the body and back, their bevelled margins, flat surfaces, 



