‘142 
Case and 
Column of 
Drawers. 

FC 
FC 


Reference to McCoy’s 
Synopsis: and Figures of Genera. 
p- 208, 
as P. globosus. 

SILURIAN. 
Names and References; Observations, &c. 


nature of the order, composed of bivalves 
which are opened along the hinge line and 
soldered there. Each dorsal valve therefore 
represents an entire bivalved shell; and 
the ventral valve represents the calcified 
foot of ordinary bivalves. (Salter, in Camb. 
Phil. Trans. 1869.) 
Pentamerus Knightii, Sow. (Min. Conch. 
1813, Vol. 1. pl. 28, Siluria, 2nd ed. pl. 
21, fig. 10, Davidson, l.c. pl. 16, 17, 19). 
The largest Brachiopod in the Silurian 
rocks. And the same species, or one very 
nearly allied (P. conchidiuwm), ranges up to 
the Arctic regions, and was brought thence 
by the discoverers in the Arctic expedition. 
Pentamerus galeatus, Dalm. (Siluria, 2nd ed. 
pl. 21, figs. 8, 9, Davidson, l.c. pl. 15, figs. 
13—22). Certainly the most common spe- 
cies, and as common in Sweden and North 
America. 
Pentamerus galeatus, Strongly plaited variety. 
(Davidson, 1. c. t. 15, fig. 19.) 
Pentamerus linguifer, Sow. (Siluria, 2nd ed. 
pl. 22, fig. 21, Davidson, l.c. t. 17, figs. 
11—14). A short broad species. 
Atrypa, Dalman. Now confined to the few 
species (the individuals are countless) which 
have the calcareous spires coiled vertically, 
ie. the apex pointing to the centre of the 
ventral valve, not horizontally as in Spirifer, 
&e. A. reticularis, Linn., is the type, and is 
world-wide, from Arctic America to Aus- 
tralia; and ranging from Llandovery or 
Upper Bala to the Upper Devonian rocks. 

Numbers and Localities. 
Rare in Dudley limestone 
or shale. 
b. 754, Walsall; a. 731— 
a. 733, Dudley, F. C.; b. 
755, Woolhope. 
a. 734, Dudley, F.C. 
a. 735, Dudley, F.C. 
