Type species: Orbitolites interstitia Lea, 1833
This genus includes the species:
| McGuirt, 1941 | Paleogene Eocene Priabonian | USA Louisiana | WoRMS 1408083 | |
| Canu & Bassler, 1920 | Paleogene Eocene Lutetian-Priabonian | USA southeast | WoRMS 1408084 | |
| (Lea, 1833) | Paleogene Eocene Lutetian-Priabonian | USA southeast | WoRMS 1413632 |
Harmer notebook - entry for Schizorthosecos
Schizorthosecos interstitia at Invertebrate Fossils of Texas