178 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY. 
Head subdensely punctate, the punctae being moderately fine and 
not sharply impressed or limited. . 
Antennae composed of seventeen articles of which the first two are 
glabrous and shining, the others being densely pubescent as usual. 
Dorsal plates from the fifth to the twentieth with the two longi- 
tudinal sulci present and complete; fine. Lateral portions of plate 
from the fifth caudad depressed leaving the lateral margin distinctly 
elevated, especially in the middle and caudal regions, but true margina- 
tion present only on the twenty-first plate. The depressed lateral 
portion of the plate rugose, the main rugae being longitudinal. The 
elevated margins, the rugae, and, less extensively, the intermediate 
surface, roughened with series of numerous spinulose points. From 
the fifth or sixth plates on a median longitudinal keel is indicated,. 
this being at first obscure but becoming more and more distinct 
caudad, while at the same time on each side of it and just mesad of 
the sulcus appears another keel, the three keels being distinct on the 
caudal segments; the keels are scabrous like the lateral portions of 
the plates. Last dorsal plate with the posterior edge moderately 
bowed out caudad and mesally truncate. With three longitudinal 
keels corresponding to those of the other plates extending from the 
anterior margin caudad two thirds the length of the plate, the plate 
caudad of their ends having a shallow pit-like depression. Keels and 
general surface scabrous. 
Sulci of ventral plates detectable only as very short traces at the 
anterior border of each. With three pit-like depressions arranged in 
a triangle as usual, these being of but moderate depth and size and not 
coalesced. In addition there are three other depressions along the 
caudal border separated from those of the triangle by a distinct trans- 
verse sulcus. On some of the more caudal plates the anterior median 
pit may be extended a considerable distance caudad as a median 
furrow. Last ventral plate conspicuously narrowed caudad, the sides 
being convex at anterior ends but straight for most of their length. 
Caudal margin with lateral halves straight and meeting in the middle 
in a slightly reentrant angle. No distinct median sulcus present. 
Coxopleurae a little extended caudad at caudomesal corners which 
are simply rounded, no distinct process being developed, wholly 
unarmed. 
Only the first pair of legs with two tarsal spines. Second to eigh- 
teenth pairs with a single tarsal spine. Nineteenth to twenty-first 
pairs unknown, being absent from the only specimen known. 
Length 57 mm. 
