PENTREMITIDEA. 213 



difficult to make out the character of tlie species from them, or from the figure of 

 Phillips's equally defective specimen, the original of which appears now to be lost. 

 At the same time their resemblances to each other are so close that there can be 

 no doubt that all four fossils belong to the same species. 



(1) The Strand specimen is the largest. It is an inside cast. It appears to 

 show a radial with the included ambulacrum, and (?) a deltoid (the division, 

 however, of which from the radial is very indistinct) and the beginning of an 

 adjoining ambulacrum. The hollows for the side-plates (and casts of the pores?) 

 are visible. 



(2) The JBradiford specimen is the cast of a single ambulacrum. It shows 

 the median food-groove and its side-branches ; the coarse crenulations upon them 

 are very evident ; the shape of the lancet-plate is perhaps discernible. 



(3) The Wrafton Lane specimen is the mould of parts of the summit, of 

 three ambulacra and of two radials. There seem to be signs of two spiracles. 

 The impressions of the ambulacra seem very perfect, and show their median groove 

 and branches, the side-plates (the marks on which are not easy to decipher), and 

 the hydrospire pores. There are also seen two deltoids (very indistinctly) and one 

 interradial sinus, the surface-ornament and the raised sides of which are very 

 evident. 



(4) Phillips's specimen appears to be lost. In his figure the ambulacra seem 

 slightly broader and more triangular. The structure shown in his enlarged 

 drawing may be either a deformity or an indication of the appearance which, 

 in some lights, the ambulacra from our Wrafton Lane specimen assume. He 

 describes " the general figure " as " oval, attenuated at the base," but does not 

 show the shape of the base in his drawing. 



Phillips identified his specimen with Pentremites ovalis, Goldfuss. 1 The resem- 

 blance, as far as the figures can be compared, is certainly considerable. In the 

 German figure, however, the ambulacra are broader and slightly more petaloid, the 

 side-branches are longer, narrower, and much more numerous, the interambulacral 

 areas are more triangular and acute, and do not extend quite so high, and the 

 ornament of these areas, though similar, is coarser. Thus Goldfuss's fossil comes 

 nearer to Etheridge and Carpenter's definition of the genus Pentremites as restricted 

 by them, and though it is not absolutely proved to be different from our English 

 species, there is the greatest probability that it is so, not only specifically but 

 generically. Moreover it is said to have come from a Carboniferous quarry, 

 though from beds in it which Professor Ferdinand Rotner thought might 

 possibly be Devonian. Under these circumstances it does not seem desirable 

 to retain the German name for our Pilton fossil. 



1 1826-33, Goldfuss, ' Petref. Germ.,' vol. i, p. 161, pi. 1, fig. 1 ci—c. 



