Simpulopsis, ii. [516]
Sinopa, N. American Tertiary, i. 134
Siphia, ii. [270]
Siphneus, ii. [230]
Siphonopsis, ii. [411]
Siphonorhis, ii. [320]
Siphonostoma, ii. [457]
Siren, ii. [411]
Sirenia, classification of, i. 89
range of Ethiopian genera of, i. 303