PALEOZOIC TIME — CARBONIC. 



675 



Among the Cephalopods, the Nautiloids, as Hyatt observes, reach their 

 greatest expansion in the Carboniferous period. They include species of 



1070-1073. 



Beachiopods. — Fig. 1070, Productus Nebrascensis ; 1071, Chonetes mesolobus ; 1072, Spirifer cameratiis ; 1073, 

 Semiimla (Athyris) subtiUta. Fig-. 1070, Hall ; 1071-1078, Meek. 



1074 



1074-1075. 



1075 



Lamellibeanchs. — Fig. 1074, Macrodon carbonarius ; 1075, Allorisma subcuneata. Fig. 1074, Cox ; 1076, Meek. 



1076-1080. 



107s 



G-ASTEOPODS. — Fig. 1076, Pleurotomaria tabulata ; 1077, Belleroplion carbonarius ; 1078, Pleiirotoinaria sphseru- 

 lata ; 1079, MacrocheOus (?) fusiformis ; 1080, Dentalium sublKve. Figs. 1076, 1077, de Koninck ; 1078-1080, 

 HaU. 



Orthoceras, Cydoceras, Phacoceras (P. Dumbli Hyatt — Figs. 1084, a, reduced 

 one half), TemnocMlus (T. crassum Hyatt, Fig. 1085), and a number of genera 

 with longitudinal ridges and keels, as in the Trigonoceratidae. There are 

 also species of the Goniatites group. 



4. Worms. — Sea-worms or Annelids have been supposed to be represented 

 by a small coiled shell, referred to the genus Spirorhis, found attached to 



