UPPER, OR FLINTY CHALK. 179 



to penetrate it. From the circumference of the opening, lines may be 

 traced, that not only pass over the whole of the spherical part, where they 

 form striae more or less distinct, but also penetrate the substance of 

 the zoophyte. There is seldom more than one opening, but instances 

 have occurred in which there were three *." The fossils represented in 

 PI. ix. figs. 1, 3, 4, 6' 8. and PL xi. fig. 8, Org. Rem. Vol. ii. belong to 

 this genus. 



22. Choanites suhrotundus. Tab. xv. fig. 2. 



Depressed, subrotund; central cavity small; external surface smooth. 



This species is generally termed " ficoid alcyonite" by collectors, 

 from its supposed resemblance to a fig. The surface is smooth, and 

 whoUy destitute of markings ; the cavity nearly circular. The depressed 

 form of the specimens is probably owdng to compression. 



In the specimen figured, three of these bodies are attached to a block 

 of chalk, of which substance they are composed. 



Localities. Upper chalk, near Lewes. 



23. Choanites^f.ri^osws. Tab. xv. fig. L 



Cyathiform, margin of the central depression marked with flexuous 

 indentations. The radical processes long, and fibrous ; base fixed by ra- 

 dical processes. 



The specimen figured is enveloped in flint. 



Localities. Upper chalk, near Lewes : very rare. 



24. Choanites Konigii. Tab. xvi. figs. 19, 20, 21. 



Inversely conical, externally marked with irregular fibres, some of 

 which penetrate the substance, and terminate in openings on the inner 

 surface; central cavity cylindrical, deep, narrow; base fixed by radical 

 processes. 



This species is for the most part enveloped in large irregular flints, 

 which exhibit but slight traces externally, of the body they enclose. The 

 superior part (fig. 19) presents a convex surface, with a cyhndrical body in 

 the centre, from whence interrupted fibres, slightly reheved, ramify in a 

 radiating manner towards the margin. At the base, numerous perfora- 



* Organic Remains, Vol. ii. p. 81. 



A A 2 



