360 ZOOPHYTES. 



lamellae twisted about the centre, deriving the name from avjepu, to 

 twist, thus departing widely from the original signification of the 

 word and genus, as introduced by Schweigger (Pal. fossils, p. 10; 

 Silur. System, 691, pi. 16 bis, fig. 4). If the genus, or its name, 

 merits a place in the science, Schweigger's characteristics of it should 

 be to some extent retained. 



GENUS VI. ARACHNOPHYLLUM. DANA. 



Cyathophy Hides aggregate, cellis kviter radiatis ; cor alii texturd cellu- 

 losd, et lamellarum subtiliter cettulosd. 



Aggregate Cyathophyllidae, having the cells faintly radiate (the rays 

 often obsolete towards the margin); texture of the corallum for the 

 most part cellular; of the radiating lamellae,, very minutely cellular. 



This genus includes the Acervularia baltica, of Lonsdale. The 

 faint rays and the general texture, seem to show a relation to the 

 Cystiophylla. The rays under a microscope appear very delicately 

 cellular (Plate 26, fig. 5, 5 a], like the finest lace-work, instead of 

 being solid plates. The stars or several polyps of a zoophyte, are 

 without circumscribed limits, in the interior of the corallum. (Silurian 

 System, pi. 16. fig. 8 to 8 e; Schweigger, Handb. p. 418). 



It is possible that these species may prove to belong to the tribe 

 Astraeacea. The absence on a polished transverse section of circum- 

 scribed limits to the stars, which appears to be a general character- 

 istic, shows some relation to the Fungidee. The texture below the 

 centre of a cell, is very imperfectly, if at all, transversely septate. 



GENUS VII. CYSTIOPHYLLUM. LONSDALE. 

 CyathophyUidce simplicissimce aut ramosce. Corolla non radiata, aut 



