R. ETHERIDGE, JtHST., 01ST ASTROCRIfflTES. 105 



publish these notes otherwise than through the regular channel. The 

 fossils in question, found by Mr. Bennie both in the Carboniferous 

 series of the Lothians and Fife, are very closely allied, if not iden- 

 tical, with the genus Astrocrinites ; but as they appear to differ in 

 certain minor points from the typical species, I have considered the 

 form to be an undescribed species, and have named it AP. Benniei, 

 after Mr. Bennie, to whose acute observation we are indebted for 

 the discovery of the specimens. Unfortunately the majority are 

 much crushed, although a few are intact; and in all, the individual 

 component parts retained in each specimen are in a fine state of 

 preservation. 



During my investigations into the structure of A?. Benniei I have 

 been favoured by Port-Major Austin with a drawing and a specimen 

 of his A. tetragonus, and by Prof. T. McK. Hughes with the loan 

 of specimens from the Cambridge Museum, which I recognized 

 in the collection when visiting that Museum some time since. I 

 take this opportunity of thanking both these gentlemen for their 

 attention and kindness. 



1. Description of the Fossils. 



(a) General Form. — The body or calyx is quadriradiate ,with con- 

 vex prominent lobes, three of which are alike and project more than 

 the fourth, which varies considerably in its structure from the other 

 three. The deep reentering angles between the lobes are occupied 

 by the pseudambulacra. The dorsal surface, or that answering to 

 the attached surface of a Crinoid, is convex, and covered by closely 

 set tubercles, but without any sign of a point of attachment for a stem. 

 The ventral surface is flattened, with a large central aperture, from 

 which radiate the four pseudambulacra. On the non-symmetrical 

 lobe, and excentric, as compared ivith the ambulacral system, is a 

 second and pyriform aperture of complex structure. 



(b) Component Parts. — It will perhaps be more intelligible if I 

 describe the plates constituting AR Benniei as those forming the 

 three symmetrical lobes and those composing the unsymmetrical 

 lobe. The minute size and crushed nature of the majority of the 

 specimens, added to the very peculiar arrangement of their parts, 

 make this anything but an easy task, which has, however, been 

 lightened by the skill with which Mr. Bennie has sifted and washed 

 samples of the disintegrated shale in which A?. Benniei occurs, and 

 so obtained some, at least, of the plates in a free and separate con- 

 dition. Immediately surrounding the central aperture, on the ven- 

 tral surface, and in the angles between the ambulacra, are what I 

 have, for the want of a better term, called the three " spearhead- 

 shaped " plates {a, figs. 5 & 8), from their general resemblance to 

 the head of a spear, having a small truncated base, constricted shaft, 

 and expanded head. We have never succeeded in obtaining these 

 little plates separate, but only in conjunction (a, fig. 8) with thoso 

 next about to bo described. These "spearhead" plates are suc- 

 ceeded in radial order by three larger pieces (b, figs. 1, 4, 5, & 8), 

 thick, strongly arched, and convex, ornamented along the median 



