

218 



DEVONIAN FAUNA. 



become cimeate, and at last definitely biserial, and the arms do not appear to 

 branch again. The greatest portion of these longer arms is clothed by exceedingly 

 fine and elongate, close-set, hair-like pinnules, with ten or fifteen long segments, so 

 that they have much the appearance of a feather from a bird's tail. These arms 

 are totally different in general aspect from those of Actinocrinus Porteri. 



Mr. Bather, who has kindly examined the specimen, expresses the arm-formula 

 thus : 



TWv _TrRp _/ thick m Br -- IV B - (F.)-pmnules. 

 " \tliin III Br. (F.)— P pinnules. 

 To what genus this fossil belongs is most uncertain. There seem some slight 

 grounds for supposing that it might belong to Rhodocrinus, and therefore with 

 much hesitation I have placed it tentatively there. 



II. Family — Batocrinidj:, Wachsmuth and Springer, 1897. 

 1. Genus — Megistocrinus, Owen and Shumard, 1852. 

 1. Megistocrinus ?, sp. Plate XXXVII, fig. 5. 



Remarks. — In the Woodwardian Museum, from Barnstaple, is the imperfect 

 cast of the dorsal cup of a Camarate Crinoid which measures about 10 mm. wide, 

 and which appears to be distinguished from Actinocrinus Porteri by the much more 

 uniform size of its plates. 



In this specimen (taking a single ray) the lowest plate seen appears to be 

 a radial, which, however, is almost destroyed ; this is followed by a small hexagonal 

 first primibrach, and this by a similar sized, polygonal, axillary primibrach. 

 This, again, is followed by two pairs of hardly smaller secundibrachs, the first 

 hexagonal, the second axillary ; and between these are three or four small inter- 

 axillary plates. The interambulacral plates in the adjoining area (which may 

 be an anal area ?) are very numerous; there seem three in the second row, and 

 four in the third and fourth rows. 



It seems, as far as can be judged, sufficiently like a Megistocrinus to be placed 

 tentatively in that genus. 



