22 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY. 



BUETHOBIUS CONIUGANS Chamberlin. 

 Can. entom., 1911, 43, p. 383. 



DIAGNOSIS. Light orange, with head and caudal segments darker; 

 antennae and legs yellow, except anal pair of latter which are orange. 

 Slender; 8f times longer than width of tenth plate; only slightly 

 narrowed cephalad. Antennae normally less than half the length of 

 the body; articles 43-45; hairs shorter than in oabitus. Prosternum 

 twice as wide as long; teeth 3+3, small. Legs all long and slender. 

 Anal legs slender and about half the length of body. First thirteen 

 pairs of legs with tibial process. Coxal pores 2, 2, 3, 2-3, 3, 3, 3. 

 Gonopods of male well clothed with long bristles; ultimate article 

 terminating in a straight spine which may be a little bent at end. 

 Gonopods of female with claw long and acutely pointed and strongly 

 curved; spines conical, flattened distad. Length 8-10 mm. 



DESCRIPTION. Light orange with caudal segments darker. Head 

 also darker but with the frontal region pale. Antennae and legs 

 yellow, darker proximally; caudal pairs of legs darker, orange, espe- 

 cially proximally. 



Body slender, being about 8f times longer than width of tenth plate; 

 only little narrowed cephalad. Entire body sparsely clothed with 

 short among longer coarser hairs; more densely clothed as usual on 

 legs where the longer coarse bristles are more abundant on ventral 

 surface of tibia and proximal joints than on the dorsal surface; hairs 

 on tarsi shorter, a pair of coarse ones on ventral surface marking the 

 junction of the two more or less consolidated articles with often a pair 

 distad of this. (See Plate 4, fig. 3) . 



Head subcordate; widest near middle, caudad of where the sides 

 are nearly straight and a little converging, while cephalad the head 

 is strongly narrowed; caudal margin a little excurved. Wider than 

 long in about ratio 40:39. 



Prosternum twice as wide as long. Anterior margin wide, not much 

 extended cephalad; angularly incised at middle. Teeth 3+3, small, 

 subequal, the outer farther from the middle one than the latter from 

 the most mesal. 



Organ of Tomosvary large, circular, and colorless ; on ventral border 

 of head at level of greatest width. 



Antennae nearly always considerably less than half the length of the 

 body, the average ratio of length of body to that of antennae being 

 near 2.45:1, the limits observed being 2 and 3 respectively to 1, the 



