248 GEO. H. HORN, M. D. 



I.YROSOMA Mann. 

 Head oval, jn-ominent, slightly narrowed behind the eyes which are round, 

 not large and very feebly convex. Labrum deeply emarginate. Maxillary palpi 

 moderately long, first joint very small, second moderately elongate, gradually 

 stouter to tip, third much shorter, fourth nearly as long as second, cylindrical, 

 slightly flattened and obtuse at tip. Antennae slender, half as long as the body, 

 second joint shorter than the third, joints 3—8 gradually shorter, 9 — 11 a little 

 broader, the eleventh longer than the tenth, oval, acute at tip. Legs slender. 

 Tibise notspinulose externally, spurs slender not long, tarsal claws slender and 

 moderately long. Form elongate, recalling Atranu.s, body apterous. 



li. opac*uiii Mann. — Elongate, brownish or piceous, subopaque, surface 

 glabrous. Head sparsely punctate. Thorax subcordate, as broad as long, apex 

 and base equal, sides strongly arcuate in front, sinuate posteriorly, hind angles 

 acutely rectangular, disc feebly convex, a slight impression within the hind 

 angles and an obsolete median line, surface rather irregularly moderately 

 densely punctate. Elytra oblong-oval, deeply striate, striae j)unctured, intervals 

 convex. Body beneath not densely punctate, with very indistinct pubescence. 

 Legs paler. Length .28— .30 inch; 7— 7.5 mm. (PI. V. fig. 11). 



In tlie males the anterior and middle tarsi have the first three joint.s 

 dilated, more broadly in the former, the posterior tarsi are slender and 

 long in both sexes, with the first joint, not longer than the second. 

 In the female the anterior and middle tarsi although not dilated are 

 somewhat broader than the posterior. 



Occurs in Alaska. 



Tribe III. — Pi'nodythn. 

 Anterior coxse transverse, feebly prominent, contiguous, with large trochantin, 

 the cavities strongly angulate externally and narrowly open behind. Middle 

 coxse oblique, not prominent, moderately separated, the mesosternum flat and 

 with an obtuse carina which extends also to the metasternum. Posterior coxse 

 not prominent, separated by a distinct intercoxal process, oval at tip. Abdomen 

 with six segments, the sixth feebly visible, the first moderately long. Antenuse 

 inserted under a frontal margin. Eyes entirely absent. 



This tribe has been instituted for the reception of a small insect 

 which refuses by its organization to enter any of the tribes as at pres- 

 ent constituted. The form is nearly that of a depressed Ftomajjhagus, 

 the head and antennse rather Anisotomide. The anterior coxse are 

 very feebly prominent as in many Auisotomidse. the trochantin is large 

 and finally the cavities are open behind. It seems, therefore, from its 

 entire organization, to be an osculant tribe with affinities equally strong 

 in the direction of the Silphiui, Anisotomini or Cholevini. 



PlBfODYTES n.g. 



Head short, oval, not prominent, not narrowed behind, eyes entirely wanting. 



Front margined at the sides. Labrum short, transverse, truncate. Mandibles 



feebly prominent. Maxillary palpi of moderate length, stout, first joint very 



short, second obcouical, third nearly square, fourth as long as the two preced- 



