12 The Craspedosomatidse of North America. 



Mentiim semi-elliptical, about twice as broad as long. It is difficult to de- 

 termine the posterior edge, as the chitin is gradually thinner, passing into a 

 transparent membrane. A cross-section, however, shows that the chitinized 

 membrane extends back to a transverse ridge and furrow, giving the mentum 

 the proportions assigned above. 



Promentum obsolete, the pointed triangular space between the rounded an- 

 terior edge of the mentum and the lingual laminae is covered by a transparent 

 membrane, sometimes appearing chitinized, but not to the same extent as the 

 surrounding parts. 



Stipes of gnathochilarium with two cardos, an exterior, subtriaugular, and 

 a larger interior, sharply serrated along its anterior edge (see plate). Includ- 

 ing the processes, the stipes are five times as long as their greatest width, which 

 occurs anteriorly; sparsely hirsute posteriorly with short bristles; a row of 

 longer bristles along the lateral margin anteriorly; one long bristle about the 

 middle, considerably removed from the anterior margin. Exterior process 

 ■with nine cones, 4 on the apex, the others on the exterior face. Interior pro- 

 cess thicker than the exterior, with 12-10 cones, all on the apex. 



Lingual laminae about three times as long as broad, the anterior and pos- 

 terior edges nearly straight, converging mesad ; a few ( 7-8 ) scattered bristles, 

 a very long one near the anterior- exterior corner. Lingual lobes semicircular, 

 subequal to base of inner process ; with 4-5 cones, the inner of which is larger, 

 longer, shari)-pointed and curved mesad. 



Middle lobe of tongue subequal to the lingual laminae, equal in width, to 

 inner process; anterior edges straight, meeting at a right angle, or rounded. 



Lingual process longer than broad ; middle tooth large, one or both of the 

 small lateral teeth frequently obsolete. 



Second segment about half as long as the first, the two outer bristles located 

 on the upper side of the carina, the second nearly directly cephalad from the 

 first, the third about midway between the first and the median line. 



Third and subsequent segments gradually longer, and with larger, some- 

 what oblique, carinae, on which the two outer bristles are located. The third 

 bristle is gradually farther away from the median line on the succeeding seg- 

 ments, and directed more obliquely backward. The anterior subsegments 

 have about five transverse parallel lines connected by fine longitudinal lines. 

 Beginning at the middle of the first segment, and extending caudad over all 

 the segments except the anal, is a fine median ridge, with a fine furrow on 

 each side. Near the ventral edge of each segment, beginning with the second, 

 is a thin oblique carina, nearly parallel to the thickened ventral margin, so 

 that its posterior end is higher; this carina has a downward curve or angle on 

 the anterior segments, and is straighter on the posterior. 



Posterior segments have the carinae gradually smaller, and the middle pair 

 of bristles come closer to the median line. The surface of all the segments is 

 finely areolate ; on the lateral and ventral surfaces are fine parallel furrows 

 suggesting the striated condition in lulidse. Posterior middle portion of the 

 segment frequently with a few oblique wrinkles or depressions. 



Antepenultimate segment shortest, without keel, that is the surface be- 



