on the Organic Composition of Chalk and Chalk Marl, 303 



Familia XL Helicotiiociiina*. 



Gen. 3. Polystomella, ? Amphistegina, ? Geoponus. 

 Familia XII. Alveounea. 



Gen. 2. Melonia, Alveolina. 

 Familia XIII. Fabulaiuna. 



Gen. 2. Fabularia, Coscinospira. 



Ordo II. — Gymnocoii^. 



Libere vagantes, nudae. 



Familia I. Cristatellina. 



Gen. 2. Cristatella, Zoobotryon. 



Ordo III. — Thallopodia. 



Stolonibus thallove membranaceo affixa, incrustantia 

 nee adnata, sed loricata. 



Familia I. Halcyonellea. 



Gen. 8. Halcyonella, Vesicularia, Bowerbankia, Far- 

 rella (= Lagenella) *, Valkeria, Stephani- 

 dium, n. G., Dynamene, Halodactylus (= 



Alcyonidium). 



Ordo IV. — Scleropodia. 



Stolonibus destituta, excreto fulcro axique anorganicis 

 firmiter affixa eisque fruticulosa. 



Familia I. Myrioporina. 



Gen. 9. Hornera, Idmonea, Retipora, Distichopora, 

 Myriopora, Tilesia, Cricopora, Ceriopora, 

 Spiropora. 

 Familia II. ? Antipathina. 



Gen. 1. Antipatbes. 



" The two last orders, the Thallopodia and Scleropodia," 

 the author observes, " are considerably richer in forms, and 

 it would be very easy by an uncritical compilation to enlarge 

 greatly the number of names ; but such confusion has been 

 produced in names by Lamouroux and later writers, the same 

 body being often designated by many new names, that I shall 

 not venture to extend my judgment further at present. What 



* The name Lagenella was appropriated to an infusorial form in 1832. 



t Melicerta is already employed among the Radiaria, Melicertuvi with 

 the Acalepha, Melicerita is not correct in language. 



Perhaps hereafter it may be advisable to substitute Textilaria for Tex- 

 tularia, Po/i/stqinatium for Polystomella, Cyclodiscus for Discorbis, &c. 



