196 KING AID [374] 



Abdominal segments from fifth to seventh cylindrical, subequal ; 

 dorsal scutes transversely oval, lateral margins rounded, traversed by 

 two delicate transverse ridges each of which bears a series of long 

 hairs, the two series uniting towards the outer margin; pleural 

 schlerites two on each side, convex, prominent, oval, oblique ; ventral 

 schlerites five on each segment, convex, corneous, the anterior large, 

 cordate, the posterior pair triangular, the lateral pair elongate ly ovate ; 

 eighth segment resembles seventh but is longer, the ridges are absent 

 and the rows of hairs are not so clearly defined, the lateral scutes are 

 reduced to one and the ventral scutes are small and indistinct. The 

 ninth abdominal segment is nearly as large as the pronotum but smooth 

 and shining, semicircular in outline, the posterior margin projecting 

 over and hiding from view the anal structures, a row of hairs along 

 the outer border; anal organ circular, convex, triangularly fissured, 

 thus forming three papillae, the posterior pair of papillae bearing disc- 

 shaped depressions serving in locomotion. 



Described from larvae found beneath moss on St. Paul Island, 

 Alaska, in the month of August. The larvae construct small cham- 

 bers in the soil in which they lie, and from the fact that the imagoes 

 were emerging at the time they came under observation, the adults 

 probably winter over in the burrows. The mandibles of the young 

 larva differ considerably from those of the adult, and a figure of the 

 former is given for comparison. 



What purports to be a description of the larva of Byrrhus fascia- 

 tus Fabr., is given by Xambeu, 1 but as there appear to be some 

 structural differences between the larva described by the above writer 

 from France and those taken in Alaska, it was deemed advisable to 

 describe and figure the latter carefully in order to furnish a basis for 

 comparison between the American and European forms. As no 

 figures are given by Xambeu, it is difficult to make a detailed compari- 

 son at present. 



HYPNOIDES MUSCULUS Esch. 

 [Plate XXV, figs. 3-7.] 



Larva white except head, pronotum, and terminal abdominal seg- 

 ment, which are yellow ; form elongate, slender, cylindrical, tapering 

 but slightly at either end. Length 7 mm. 



Head squarish in outline, narrower than the pronotum, flattened 

 above and beneath, smooth with a few scattered hairs. Clypeus 



1 Ann. Soc. Linn. Ljon., XLII, p. 60, 1896. 



