RAYMOND: NEW AND OLD SILURIAN TRILOBITES. 19 
has short glabellar furrows and no lip on the free cheek, while B. dayi 
has long furrows and a lip on the free cheek. The eye of B. decipiens 
seems also to be a little longer and further back than in B. dayi. The 
pits in front of the eyes are exceedingly faint. 
Bumastus transversalis (Weller) likewise has a short head, large 
eyes, and short dorsal furrows, but is much wider than B. decipiens. 
B. armatus (Hall) is much like B. decipiens but has spines at the genal 
angles. 
Measurements: —The holotype (Plate 1, fig. 2) an imperfect 
cranidium, is 19 mm. long; the eye is 7.5 mm. long, and 2 mm. from 
the posterior margin. The figured paratype (Plate 1, fig. 1) is about 
51 mm. long; cephalon 21 mm. long; thorax 15 mm. long. A second 
small, unfigured paratype has the cephalon 12 mm. long, 16 mm. 
wide; eye 5 mm. long; 1 mm. from posterior margin; thorax 8 mm. 
long; pygidium 12 mm. long, and about 16 mm. wide. 
Formation and locality: — All the specimens are from the Niagaran 
at Wauwatosa, Wisc. 
BUMASTUS TENUIS, sp. nov. 
Plate 1, fig. 6, 7 and ?11. 
This species is like B. deciiens, rare, and the collection contains 
five specimens showing the cranidium only. It is characterized by 
its slight convexity and the very wide concave lip at the front. The 
dorsal furrows are long, reaching to the pit in front of the eyes. These 
pits are themselves very far forward and close to the margin. The eyes 
are large and close to the posterior margin. 
This species of course suggests B. cuniculus, but the lip is much 
wider, the dorsal furrows longer, and the pits in which they end very 
close to the margin. It has a flatter cephalon and wider lip than any 
known Bumastus. 
A pygidium (Plate 1, fig. 11) which does not seem to belong with any 
other species found at Wauwatosa is tentatively referred to B. tenuis. 
It is too short and not convex enough for B. niagarensis, and has too 
wide a concave border for B. cuniculus, B. dayi, or B. decipiens. 
- Measurements: — The type cranidium is 33 mm. long and 34 mm. 
wide at the palpebral lobes. The eye was approximately 8 mm. long 
and 2 mm. from the posterior margin. 
Formation and locality: — All the specimens are from the Niagaran 
at Wauwatosa, Wisc. 
