MESOZOIC TIME — CRETACEOUS. 



848 



long ; and 1396, S. larvoeformis, another, showing more decidedly the imper- 

 fectly coiled condition, from the Fort Benton group. Fig. 1397 is an Ammo- 

 noid in which the form is straight, and hence the name Baculites, from 

 the Latin baculum, a walking-stick. The length of this Baculite is over a 

 foot, and the diameter 2^ inches ; other associated species are more than a 

 yard long. Another species, common in New Jersey, is the B. compressus 

 Say, and Fig. 1399 is a section of it. A young stage of it is represented, 

 enlarged, in Figs. 1398, a, by A. P. Brown (1891) ; the specimens were from 

 the Black Hills, S. D. ; they show that the animal in the young stage has a 

 perfectly coiled shell. Others of these partly uncoiled kinds are represented 

 on page 862. Fig. 1400 is a Nautilus from the Lower Greensand, New 

 Jersey. 



Vertebrates. — 1. Fishes. — In addition to Selachians and Ganoids there 

 were Teleosts, or Osseous Fishes, the tribe which includes the lai'ger part 

 of modern fishes, and nearly all edible species. The Cestraciont Sharks 

 still continue ; and the bony pavement pieces of the mouth are not rare 

 fossils. Two views of one from New Jersey are given in Figs. 1406, 1406 a. 



1401-1406. 



1406 



1406 rt 



Sqfalodont Selachians. — Fig. 1401, Otodus appendiculatus ; 1402 a, 6, Lamna Texana ; 1403, Corax hetero- 

 don ; 1404, Otodus appendiculatus ; 1405, Oxyrhina Mantelli. Cestraciont Selachian. — Figs. 1406, 1406 a, 

 Ptychodus Mortoni. Fig. 1401, Gibbes ; 1402-1405, Ecemer ; 1406, Morton. 



Many of the Sharks were of the modern tribe of Squalodonts — distinguished 

 by the sharp cutting edges of the teeth, and other peculiarities. One kind 

 is represented in Figs. 1401 and 1404 of the genus Otodus, the latter from 

 Texas; 1403, tooth of a Corax; 1405, of an OxyrMna; 1402 a, b, oi Lamna 

 Texana. 



The Teleosts of the Middle and Upper Cretaceous of North America in- 

 clude species of the Mullet family, represented by Beryx inscidptus Cope, 

 from New Jersey ; the Sphyrenids of several large species described by Cope, 

 of the genera Pachyrhizodus, Empo, and others, from Kansas ; the Siluroids, 

 powerful carnivorous fishes, called Saurodonts by Cope, one of Avhich, Por- 

 theus molossus Cope, from Kansas, had the vertical diameter of the head 



