312 
The tergum has a beaklike but not very longapex; the spur 
fasciole is broad, and distinet, although not very deep; the ridges 
of growth are clean cut, but there are no longitudinal striæ pres¬ 
ent. The spur is broad, about one third of the basal margin, and 
separated from the basiscutal angle by an oblique part of the 
margin almost as long as the width of the spur. The articular 
ridge is well developed, but the interior side otherwise only feebly 
sculpturated; no crests are present for the depressor muscle. 
The scutum has no radial stripes nor grooves, but only prom¬ 
inent ridges of growth. It makes a sharp bend along a radial line 
so that the tergal third stands almost perpendicularly to the rest 
of the plate. There is a great, and rather deep pit for the adductor 
muscle; the adductor ridge is short, but prominent, and in its in- 
ferior part separated from the very prominent articular ridge by 
a deep exeavation; this exeavation upwards passes into a narrow 
and not very deep furrow running to the apex. The articular fur- 
row is very shallow. There is no pit for the depressor muscle. 
The greater diameter of the present specimen is 17 mm between 
the lateral plates, the rostro-carinal diameter 16 mm, and the height 
of the carina 10 mm. It ought to be remembered -that these dim¬ 
ensions have been somewhat larger in the intact specimen, as the 
basal part is now wanting. 
An examination of the animal showed that the labrum (Fig. 55) 
has a deep notch; close by the notch the margin has on each 
side three low transversal ridges, each with a rudimentary dent- 
icle at its top. 
The mandible has two large upper teeth; near the lower 
angle two olher teeth are indicated; the lower angle has evidently 
had numerous small, spinelike or hairlike denticles, now worn off. 
Near the cutting edge, and almost parallel with it runs a narrow 
belt of rather long hairs. 
The maxi 11a is rather characteristic and aberrant. There are 
two large upper spines, the lower situated a little obliquely at the 
lower side of the marginal main spine. Below these two spines 
three or four pairs of somewhat shorter spines follow and then, 
along an oblique median part of the cutting edge two or three 
more siender, but longer single spines. The lower half of the cut¬ 
ting edge is somewhat protruded and armed with four large spines 
