BY DR. R. VON LENDENFELD. *2 2 3 



1. SUB-FAMILY. MONOGROPTINJE. 

 MONOGROPTIDvE. Lapworth. 



Developed one-sided ; pointed ends of the Sicula pointing 

 upwards, united with the dorsal margin of the proximal end of a 

 single or composite Hydrosome. 



Monograptus. Geinitz. 



Rostrites. Barrande. 



Cryptogi'aptus. Carruthers. 



Azygograptus. Nicholson. 



Dimorphograptus. Lapworth. 



2. SUB-FAMILY. LEPTOGRAPTIN^E. 

 LEPTOGRAPTID.^. Lapworth. 



Hydrosom bilateral, with irregular branches. Cells apart, just 

 touching. Sicula persistent in the axilar. The broad part 

 forming the proximal end of the Hydrosome. 



Leptograptus. Lapworth. 



Amphigraptus. Lapworth. 



Pleurograptus. Nicholson. 



Nemograptus. Emmons. 



Coenograptus. Hall. 



3. SUB-FAMILY. DICHOGRAPTESLE. 

 DICHOGRAPTID^E. Lapworth. 

 Bilateral. Branches of regular cells, very dense, rectangular 

 Sicula persistent. Its point at the proximal end of the Hydrosome. 

 Didymograptus. McCoy. 

 Trichograptus. Nicholson. 

 Tetrograptus. Salter. 

 Goniograptus. McCoy. 

 Schizograptus. Nicholson. 

 Temnograptus. Nicholson. 

 Ctenograptus. Nicholson. 

 Dichograptus. Saltei*. 

 Lagonograptus. Hall. 

 Clonograptus. Hall. 

 Clematograptus. Hopkins. 

 Cladograpsus. McCoy 



