56 INTRODUCTION. 
linea subulata excavata longitudi- 
Dali. 
GEN. 14. Pinna.—Animal limax; tes- 
ta subbivalvis , fragilis, erecta , 
emittens barbam byssinam ; cardo, 
edentulus, coalitis in unam val- 
vulis. 
SECTIO TERTIA.—Testacea unival- 
via spira regulari, seu cochleæ. 
GEN. 1. Argonauta.—Animal sepia ; 
testa univalvis, spiralis, involuta , 
membranacea, unilocularis. 
Gex. 2. Nautilus.—Animal incertum; 
Rumpbh. mus. tab. 17.fig. C. Testa 
univalvis, isthmis perforata conca- 
merata, polythalamia. 
GEx. 5. Conus.—Animal limax; testa 
univalvis , convoluta , turbinata; 
apertura effusa, longitudinalis, li- 
nearis, edentula , basi integra; co- 
lumella lævis. 
GEN. 4. Cypræa.—Animal limax; tes- 
