264 PEOF. W. J. SOLLAS ON BRAHMACRINUS [May 19OO, 



15. Fossils in the Oxford University Museum. — II. 1 On Two 



New Genera and Species of Crinoidea (Brarmacrijsius pon- 



derosus and Cicero crintjs elegans). By Prof. W. J". 



Sollas, M.A., D.Sc, LL.D., F.K.S., Y.P.G.S. (Read January 



24th, 1900.) 



[Plate XVI.] 



I. Brahmacrinus fonderosus, gen. et sp. nov. 

 (PI. XYI, rigs. 1 & 2.) 



This somewhat barbarically ornate crinoid is represented in the 

 University Collection by two calyces, which are both devoid of arms 

 and stem. One of the specimens is exceedingly well preserved, and 

 affords a fairly complete knowledge of the structure of the calyx. 

 In the British Museum (Natural History) five specimens of the 

 same crinoid are displayed ; these also are calyces without arms or 

 stem. Some of the specimens in the British Museum were obtained 

 from Preston (Lancashire), and some from Yorkshire ; those in the 

 Oxford University Museum are from the latter county, where they 

 occur in the Carboniferous Limestone. 



The size of the calyx is fairly constant in all specimens, mea- 

 suring, in that selected for description, 45 mm. in height by 40 mm. 

 in maximum breadth. The dorsal cup is obconic in form, with the 

 apex (corresponding to the base of the crinoid) truncate ; the ventral 

 disc is gently convex, and supports an excentric anal tube. 



The basals are large, and three in number ; two are equal in size 

 and larger than the third, which is the left anterior. The sutures, 

 which are persistent, are not quite symmetric with regard to the 

 radial plates, which they meet on one side of the median line. The 

 basals, like the other plates of the calyx, are much swollen, except 

 immediately over the sutures, which consequently lie at the bottom 

 of a deep groove. 



The live radials are also large, 13 mm. in height by 18 mm. 

 in maximum breadth, very thick, but marked by a transverse cre- 

 scentic depression, which lies in the upper half of each plate. Owing 

 to their contact with more than one interradial plate the outline of 

 the basals is many-sided, usually octagonal. The upper median 

 facet is slightly curved for the reception of the single costal, a 

 much swollen plate, scarcely 9 mm. broad and 5 mm. high. It 

 is completely incorporated in the calyx, forming an integral part of 

 the wall. 



The distich als are two in number, of the same breadth, namely, 

 5 mm., and the first is 3*5 mm. in height ; they also form part of 



1 No. I, on Silurian Echinoidea & Ophiuroidea, was published in Quart. 

 Journ. Geol. Soc. vol. lv (^1899) p. (592. 



