516 Prof. F. J. Bell on a Species of Echinocardiuin 



surface, but more particularly by a comparatively thick layer 

 of the same substance internally ; continuous over one part 

 and cribrated with large holes in another, opposite to corre- 

 sponding holes in the cortex, rendered more or less polygonal 

 by the intercrossing of the arms of the large radiates, and 

 through whicli the cribriform areas of the surface can be seen. 

 Spicules of two kinds, viz. triradiate and quadriradiate : — 1, 

 triradiates of different sizes, mostly regular in form and 

 mostly large ; ray 90 by 15-6000ths : 2, quadriradiates of 

 two sizes, viz. very minute and very large; the former nume- 

 rous, sagittal in shape, averaging only 10 by l-6000th in the 

 shaft, with arms respectively about half this length, and the 

 latter, which tends more to a regular form and is scant, with 

 arms 150 by 21-6000ths. No. 1 is chiefly confined to the 

 cortex, the minute form of no. 2 to the sarcodic lining of the 

 interior, with the large form here and there in the interior of 

 the cortex. Size of specimen, which altogether is irregularly 

 oblong, about IJ x | x ^ inch. 



Ohs. The structure of this species, if not abnormal, is very 

 uncommon, on account of the general form in combination 

 with such a thin wall ; not less so the layer of sarcode over 

 the inner surface, which is charged with the minute quadri- 

 radiates confusedly distributed throughout its substance, hence 

 indicative of an abnormal condition. In general form, that 

 is in outward appearance, it is very much like Pol^jaeff's 

 Heterojjegma nodus gordii (' Challenger ' Reports, 1883, Cal- 

 carea, p. 45, pi. i. fig. 7, and pi. iv. tig. 1), which also came 

 from Australia, viz. from off'' Cape York " at the N.E. angle, 

 since that from the Bermudas appears to have been too much 

 injured for illustration, but when anatomically examined 

 proves to be totally different, as may be seen by the descrip- 

 tions respectively. 



[To be continued.] 



XLVIII. — On a Species o/Echinocardium from the Channel 

 Islands. By F. Jeffeey Bell, M.A. 



Some weeks ago I received from Mr. Fiulay of the Watt 

 Museum at Greenock, an exceedingly fine specimen of Echino- 

 cardium, which he asked me to determine for that institution. 

 A very superficial examination of the object showed me that 

 it was altogether unlike any specimen in the British Museum, 

 and that it could not be readily assigned to any described 



