
Parr IL, Szor. iv. § 1.] CARBONIFEROUS. 728, 
- masses forming beds of limestone. The chief genera are Spirorbis, 
_ Serpulites, Ortonia, Vermilia.' Polyzoa abound in some portions of 
aS 
y / Hy i IN LAN Wl! wy 
} Mit AAS \ \) 
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Fig. 336.—CARBONIFEROUS BRACHIOPOD. 
a, Spirifera hysterica (Schloth.); 6, Do. interior of dorsal valve, showing spiral calcareous 
supports for the arms; c, Terebratula hastata (Sow.); d, Productus giganteus (Martin). 
the Carboniferous Limestone which were almost entirely composed of 
them, the genera Fenestella, Sulcoretopora, Vincularia, Polypora, 
Diastopora, and Glauconome being frequent. 
Of the brachiopods some of the most com- 
mon forms are Productus, Spirifera, Rhyn- 
chonella, Athyris, Chonetes, Orthis, Lingula, 
and Discina.” But the higher molluscs now 
begin to preponderate over the brachio- 
pods. The lamellibranchs in the English 
Carboniferous Limestone number 49 genera 
and 334 species, including forms of Avicu- 
_lopecten, Leda, Nucula, Sanguinolites, Lepto- 
domus, Schizodus, Edmondia, Modiola, and 
Conocardium. The gasteropods in the same 
rocks amount to 206 species belonging to 
29 genera, among which Huomphalus, Natica, Fis. 337.—CAaRBoNTFEROUs 
° A LAMELLIBRANCHS. 
Plewrotomaria, Macrocheilus, and Loxonema b Conukasaniis epee 
1 R: Etheridge, Jun., Geol. Mag. 1880, p. 110. (Goldf.) ; b, Aviculopecten 
2 Productus is almost wholly Carboniferous. Other sublobatus(Phill.), showing 
genera had already existed a long time; some even of — colour-bands. 
the species were of ancient date—Orthis resupinata of 
the Carboniferous Limestone and the Devonian 0. striatula and Strophomena depressa 
had survived, according to Gosselet, from the time of the Bala beds of the Lower Silurian 
period. Gosselet Hsquisse, p. 118. 
3A 2 

