212 DEVONIAN FAUNA. 



is the base visible, though enough of the radial plate is seen to show that the 

 basal parts were probably at least slightly extended beyond the extremities of the 

 arms. 



It seems to differ from most species of Pentremites by the narrowness and 

 arrangements of its arms ; from most species of Pentremitidea by the length of its 

 sinuses, and from most species of Mesoblastus by the width of its arms, the apparent 

 shape of its spiracles, and the probable presence of an under-lancet-plate. On the 

 whole there seems to be least difficulty in assigning it for the present to the genus 

 Pentremitidea, but this must only be regarded as a provisional arrangement until 

 the discovery of specimens sufficiently perfect to decide the point. 



1. Genus PENTHEMITIDEA, d'Orbigny, 1849. 

 1. PENTREMITIDEA PHILLIPSII, n. sp. Plate XXIX, figs. 5, 5 a, 6. 



1841. PENTBEMITES OVALIS, Phillips (not Goldfuss). Pal. Foss., p. 29, pi. xiv 



figs. 40 a, b. 

 1886. Etheridge and Carpenter. Catal. Blast. Brit. Mus., p. 129. 



Description. Calix probably more or less prolately spheroidal ; summit flatly 

 convex, broad ; base unknown. Ambulacra (i. e. ambulacral areas) moderately 

 broad, rather rapidly tapering, extending very far down the calix. Radial plates 

 very large; bodies convex, much shorter than the limbs. Limbs very long. 

 Interradial sinuses elongate, lanceolate, with sharp raised margins, not reaching 

 far into the summit, and slightly narrower on the whole than the ambulacra. 

 Deltoids indistinctly seen, very small, apparently irregularly rhombic. Spiracles 

 apparently subcentral, undivided by septa, situate above the tops of the deltoids. 

 Lancet- plate exposed, with a central groove and with rather distant branches, 

 both being margined with long and coarse crenulations (which seem also to 

 extend to the side-plates). Side-plates squarish. 



Three or four hydrospire-folds seen at the distal extremity of one of the 

 ambulacra, probably exposed by the breaking off of part of the under-lancet-plate, 

 which appears to cover all the area between the side-plates. Radials marked 

 with microscopic rounded lineations, slightly radiating towards the sides of the 

 interradial sinus. 



Size. A specimen appears to be about 7 mm. long. 



Localities. In the Barnstaple Atheneeum is a specimen from Strand, Ashford, 

 and another from Bradiford; and in my Collection is one from Wrafton Lane. 



Remarks. These specimens are all fragmentary, and consequently it is very 



