UPPER CAMBRIAN. 



68 
Sreeaen Reference to McCoy's 
Drawers, | Synopsis: and Figures of Genera. 
Gm Pl, 11, fg, 25; pr3il: 
G As B. ornatus, 
p. 310. 
B. expansa, p. 309. 
case Univalve shells, 
G spiral shells. 
Gm Pleurotomaria, p. 291. 




Names and References ; Observations, &c. 
Numbers and Localities. 

Bellerophon subdecussatus, McCoy. A form 
belonging to the subgenus Bucania, which 
has the whorls exposed in the umbilicus. 
Bellerophon nodosus, Salter (B. ornatus, McCoy, 
not of Conrad. Mem. Geol. Surv. m1. p. 349, 
woodeut 15). 
(Bellerophon globatus? McCoy is not worth 
inserting. The original species was named 
from an obscure broken B. expansus, Sow.) 
N.B. Maclurea macromphala, McCoy, should 
be placed here, for Maclurea is a Hetero- 
pod. It is probable however that this shell 
is not a Maclurea. 
Gasteropoda. 
Only the herbivorous genera, or such as by 
their round mouths appear to have been 
such, are found in the old slate rocks, Pleu- 
rotomaria, Murchisonia, and Holopea, &e. 
are probably all related to the Janthinide 
and Litorinidw, vegetable feeders. 
Murchisonia turrita, Portl. sp. (Geol. Report, 
p. 413, pl. 30, fig. 77). Rather doubtfully 
identified. 
N.B. Plewrotomaria, Murchisonia, and Hormo- 
toma, &c. include a host of species very like 
one another in habit, and living in crowds 
together, probably much in the way of the 
violet snail (Zanthina). It is difficult to dis- 
tinguish the species, unless close attention 
be paid to bands, ridges, &e. &e. The 
beaded-whorled species are distinguished as 
Hormotoma (see fig.), and these, which are 
just as common as the others, form perhaps 
a more natural group than either Murchi- 
sonia proper or Pleurotomaria. Of the latter 
genera, only the shorter forms are called 
Pleurotomaria, but these are not so T’rochus- 
shaped as the Oolitic species. 


B, IGsk4 
Meifod. 
Alt-yr-Anker, 
a. 163, Teirw River, 8. of 
Llangollen, 
A Ludlow species. 
a. 167*, Cyrn-y-Brain, 
Wrexham; Llyn Ogwen. 
Bala. 
