CARADOCIAN CYSTIDEA FROM GTRVAN. 441 



sio-nificance. The names of species subsequently described have been added in square 

 brackets : — 



(1) Pectinirhombs all, or at least on the base, conjunct. 



C. atavus Jaekel (1899). 



C. giganteus Leuchtenberg (1843, Gonocrinites). 

 [C constrictus Bather (n. sp.).] 



(2) Pectinirhombs all [? see § 802] disjunct. 



(a) Only with axial ridges between the umbones. 

 C. radiatus Jaekel (1899). 

 C. Logani Billings (1857, Glyptocystites). 

 C. interruptus Jaekel (1899). 

 C. Volborthi Schmidt (1874, Glyptocystites). 

 C. penniger Eichwald (1842, Cyathocrinitis). 

 C. granulatus Jaekel (1899). 

 C. ornatus Eichwald (1859). 

 C. Leuchtenhergi Angelin (1878, Glyptocystis). 

 G. nodosus Jaekel (1899). 



(6) With axial ridges and parallel accessory ridges. 

 C. striatus Jaekel (1899). 

 [C. angulatus Wood (1909).] 

 G. alter Barrande (1887, Homocystites). 

 C. Walcotti Jaekel (1899). 

 G. anatiformis Hall (1847, Echinoencrinites). 



(c) With cancellate ornament. 

 G. insignis Jaekel (1899). 

 G. Forhesi Billings (1857, Glyptocystites). 

 G. sculptus Schmidt (1874, Glyptocystites). 

 C. degener Jaekel (1899). 



The name " Ghirocrinus canadensis " found on pages 108 and 1 1 2 of Jaekel's " Stammes- 

 geschichte " (1899), with a reference to " Taf XL fig. 8," is probably an error for 

 G. Walcotti, p. 221, Taf XL fig. 9. No species of Gheirocrinus has been described 

 under the name canadensis. 



§ 308. Li the following table the species of Gheirocrinus are set forth according to 

 their geographical distribution and relative age. The names of the time-periods 

 are not inserted, since there is some difficulty in correlating the horizons in the 

 various countries. Our information as to the horizons of the species from the Russian 

 " Vaginatenkalk " described by Jaekel is not so exact as could be wished. Square 

 brackets indicate that the age of the contained species is uncertain : — 



