s 
SILURIAN 
5. PROSOPISCUS MIMUS. 
I 
Plate 1, figs. 19, 20. 
P. capite transverso. Glabella capite brevior, antice angusta, lobls 
lateralibus tribus compressis,—basali angusto, trigono, convexissimo,— 
reliquis transversis. 
Head transverse, tlie glabella shorter than its length, and 
narrowed in front, with a small convex forehead lobe, and 
three compressed lateral lobes, the lowest most convex and 
projecting furthest out. This lower lobe is narrow, trigonal— 
the rest are transverse. The furrows are deep and sharp, the 
front one shortened, the first (upper) lateral lobe curving 
round its end. 
Between the glabella and the cheeks in front is a small de¬ 
pressed triangular space, and the margin continues all round 
the head, of moderate thickness, a set of crenulations occur¬ 
ring in the furrow in front of the cheeks. These latter are 
wide, roughly spherical, triangular, convex and punctate all 
over, with no trace of an eye or facial suture. The posterior 
angles are a little produced, but the general form is remarka¬ 
bly oblong and transverse. 
Of the tail-piece (fig. 20) supposed to belong to this, we 
have only the lateral lobes of one side ; and no axis. It is 
probable, but uncertain, that there were only three widely- 
divergent pleurae, curved gently, divided for two-thirds their 
length into spines, and with deep short furrows (not extend¬ 
ing to the edge of the limb) between the connected portions 
of the pleurae. 
Locality .—Chorhoti Pass. Damchen (heads); above Bom- 
pras (tail). Nos. 1678, 1737, 1744.) 
6- SPHiEREXOCHUS IDIOTES 
Plate 1, figs. 21, 22. 
We have no parts of the head but the characteristic basal 
obes of the glabella, which, however, being round and convex, 
