50a GEOGRAPHICAL ZOOLOGY. [i'Aut iv. 



Family 6. — P.ELEMXITID.E. Fossil. (6 Genera, 100 



Species), 



DiSTPJBrTiON. — Lias to Chalk in Europe, India and Xorth 

 America. 



Order II.— TETRA BBA XCHIA TA . 



Family 7.— NAUTILTD/E. (1 Genus, 3 Species, Living; 4 

 Genera, 300 Species, Fossil). 



DiSTElTiUTlON. — Indian and Pacific Oceans ; and the fossil 

 species from the Silurian Period to the Tertiary, in all parts 

 of the world. 



Family 8.— OPTHOCEEATID^E. Fossil. (8 Genera, 400 



Species). 



Distribution. — LoAver Silurian to Lias. 



Family 0.— AMMONITID.E. Fossil. (14 Genera, 1100 



Species). 



I )iSTrjr.UTiox. — Pepper Sihirian to Chalk. Found at 1 0,000 

 feet elevation in the Himalayas. 



