236 SILUEIA. [Chap. X. 
headed Trilobite, found both in the Dudley limestone and its equivalent rock in 
Bohemia. And, lastly, there is a species of Bronteus, probably Br. laticauda, j 
Wahlenberg, found by my deceased friend Dr. Lloyd, in the Wenlock Limestone. 
It is figured by Professor Phillips under the name of Br. signatus (Palaeoz. Foss. 
of Cornwall, &c, f. 254). The original of this rare fossil is in the cabinet of 
Professor Tennant, of London. 
A goodly list of Trilobites of the Upper Silurian rocks has thus been given j j 
and many other forms will probably reward research. 
The small Bivalve Crustaceans, such as Beyrichia, M'Coy, Leperditia, Rou- 
ault, and Primitia, Jones, remain to be noticed. They are very numerous. The 
most abundant Upper Silurian species is Beyrichia Klcedeni, M'Coy, Foss. 64. 
f. 4, according to Professor T. Rupert Jones, our best authority on these subjects. 
It is a very abundant species from the base of the Wenlock Shale to the 
highest Ludlow stratum, varies greatly in shape, but is a good index of the 
Upper Silurian, though found sometimes in the Llandovery rocks. B. Wilck- 
ensiana, Jones, is also plentiful in the Ludlow rocks, and B. siliqua, Jones, 
has been detected in slabs of Woolhope Shale near Malvern. The Lower Silu- 
rian form, it will be recollected, is B. complicata, Salter (pp. 204, 205). Dr. H. B. i 
Holl has found many of these Bivalve Crustacea well preserved in the Upper 
Silurian limestones near Malvern; they are numerous and of a still finer 
growth in the Upper Silurian limestones of Gothland. The Beyrichiae, together ! 
with the little Primitise, and the relatively large Leperditise of Gothland, are, in 
the opinion of good naturalists, probably of the Phyllopod tribe, and more 
nearly allied to living forms than the Trilobites that accompany them. 
Fossils (66). Upper Silurian Crustaceans. 
b 
Ceratiocaris from Lesmahago — f. 1, with its 
abdomen displaced and recurved*; andf. 2, the 
carapace of another species, showing the two 
valves of which it is composed, a. Anterior, 
b. posterior end of carapace. 
So also may be some larger, shrimp-like forms, Ceratiocaris, from the Ludlow 
rocks of Ludlow, Kendal, and the South of Scotland. One of these, C. inorna- 
tus, M'Coy, is three or four inches long. The carapace, or front part only of the 
body, of this species, was described by Professor M'Coy ; but the possession of 
more perfect specimens of other species — some even of greater size — has now 
permitted the delineation of the entire form. There appears to be good evidence 
that Ceratiocaris was a Bivalve Crustacean, probably of the Phyllopod tribe. 
To the same genus also belong those curious striated crustacean spines which 
are represented in PI. XIX. f. 1, 2. They were skilfully distinguished, by 
* This position of the body at first misled ob- by Mr. Slimon from Lesmahago and now in the 
servers as to which was the front and which the British Museum, in which the maxillae are seen 
hinder end of the Carapace; but the position of within the anterior portion of the carapace, appa- 
the ocular tubercles pointed to the anterior part of rently in situ. (See Mr. H. Woodward's paper on 
the carapace; and the question has been defi- Crustacean Teeth, in the 'Geological Magazine,' 
nitively solved by the help of a specimen obtained 1865, vol. ii. p. 401, pi. 11. fig. 1.) 
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