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The scutum (PI. XVIII, fig. @ and c) has the occludent margin arched, and the tergal 
and basal margins of about the same length; there is no adductor ridge, and the articular ridge 
is feebly developed, not at all prominent. On the outer surface the growth-ridges are not very 
distinct, and no trace of striae can be observed. The whole surface is slightly arched, the 
apex curved inwards. 
The tergum (PI. XVIII, fig. 6 and @) has the scutal margin slightly convex, and the 
basal margin concave. The outer surface does not show the growth-ridges even so well as 
the scutum. The spur extends slightly beyond the basal margin, and is rather broad; its anterior 
margin is separated from the basi-scutal angle by a very short anterior part of the basal margin; 
in other specimens, however, it is confluent with the scutal margin. Crests for the depressor 
muscles well-developed. The chitinous membrane covering the tergum bears a distinct group 
of short hairs along the carinal margin, near the apex. The latter is blunt, not produced. 
With regard to the structure of the animal’s body, the following was observed: 
Mouth. Labrum (Pl. XVIII, fig. 15). The normal number of teeth on each side of the 
wide notch seems to be 3. Often, on one, or on both sides, only two of these are developed, 
in which case one of the teeth may be double-pointed. The subtriangular portion representing 
the thickened part of the labrum terminates on the inside in a somewhat narrower part, looking 
like a handle. | 
Palpi with numerous hairs scattered irregularly over large part of outer surface. There is 
no distinct tuft of longer hairs disposed’ at the distal extremity of the palpus. Shape of the 
palpus oval, with the inferior margin distinctly rounded. 
Mandible (Pl. XVIII, fig. 16) with teeth 2 and 3 double, and 3 thicker. Distance 
between extremities of teeth 1 and 2 slighty longer than that between the extremities of teeth 
2 and-3. The part behind the 3" tooth rudimentary: teeth 4 and 5 small, the inferior angle 
represented only by a minute point. 
Maxilla (Pl. XVIII, fig. 17) with the edge nearly straight, a small and shallow notch 
behind the upper pair, and 3 to 5 somewhat shorter spines situated between this notch and the 
inferior pair. The notch is narrower in some specimens than in others; as a rule one or two 
hairs are seen at the bottom of the notch. 
Outer maxillae (Pl. XVIII, fig. 18). Outer lobe relatively broad and short, obtusely 
pointed, and with the inner margin more or less straight. A moderate portion of the inner 
surface of the outer lobe is covered with hairs, from which a single or double row can be followed 
to the inner lobe. The latter is somewhat elongated towards the basis, the hairs disposed 
along its inner surface point towards the basis of the maxilla; they are more distinctly feathered 
than those of the remaining parts of the maxilla. 
Cirri. First pair has the rami unequal, of 6 to 7, and i1 to 12 segments. Anterior 
faces of the segments of shorter ramus rounded, not protuberant. 
Second pair has 7 to 8, and 8 to 9 segments in the two branches. The anterior 
faces of the segments protuberant, furnished with dense brushes of hairs. 
Third pair has 9 to 10, and 10 to 11 segments. Brushes of hairs less dense than on 
the protuberances of the segments of the second cirrus. No trace of teeth on or along the 
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