PALEOZOIC TIME — CAMBRIAN. 



475 



enlarged figures 



546-549. 



546. 



of some of the 



547. 



2. Brachiopods. — The following are 

 forms found in New Brunswick. 



3. MoUusks. — Ptero- 

 pods are still very common 

 (Figs. 527-531 ) . Two sup- 

 posed G-astropods are from 

 Xew Brunswick. Fig. 552 

 represents Stenotheca Aca- 

 dica, originally supposed to 

 be a Brachiopod of the 

 genus Discina, but now 

 placed among the Gastro- 

 pods. Fig. 553 is a greatly 

 enlarged view of Harttia 

 Mattheioi Walcott, referred 

 to the Calyptraea family, 

 the cap-like shell having a 

 smaller cap within. 



4. Crustaceans. — Some of the Paradoxides are the largest of Trilobites. 

 P. Harlani (Fig. 556), the first known of American species, from Braintree, 

 near Boston, has a length of 10 inches, and a breadth two-thirds as great, in 

 some specimens ; and the spines at the posterior angle of the cheek-piece of 



Brachiopods. — Fig. 546, Acrothele Matthewi (2); 547, Linnars- 

 Bonia transversa (8); 548, Lingulella Dawsoni (1) ; 549, 549 a, 

 Orthis (Protorthia) Billingsi. Figs. 546, 547, 549, from Walcott; 

 548, from Hartt. 



550-553. 



551. 



550. 



552. 



553. 



Pteeopods and Gastropods. — Fig. 550, Hyolithes Acadicus (1) ; 551, H. Danianus (1) ; 552, Stenotheca 

 Acadica (2) ; 553, Harttia Matthewi (12). Figs, from Walcott. 



the head (the piece bounded by a suture passing by the eye) are nearly half 

 as long as the animal. (In Fig. 556 they are shorter than usual.) P. Ben- 

 netti Salter, from ISTewfoundland, was 11 inches long and 9|- broad ; and P. 

 Regina Matthew (Fig. 557) from New Brunswick, 15 inches long and 11 

 broad. Fig. 554 shows the form of an Agnostus. In Fig. 555 the free 

 segments are absent. 



