10 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY. 



Creek! Provo!); Idaho (Pocatello !) ; Oregon (Portland!); Arkansas 

 (Little Rock, sec Bollman, but possibly not the real fulvicornis) . 



Also distributed throughout Europe. 



No male of this species has ever been recognized. The author has 

 examined more than a hundred individuals without detecting a male 

 and has sectioned a considerable number of females without finding 

 spermatozoa in the genital ducts although these are to be found readily 

 enough in female Lithobii. The present evidence lends probability 

 to the view that this species, as likely also its relatives in North Amer- 

 ica, is parthenogenetic in its usual reproduction. 



This species prefers the immediate vicinity of water although the 

 author has found it well removed from streams at times. In Wis- 

 consin it is very common among stones and sticks at edges of streams 

 and it was found in similar localities at Peoria, Illinois. At times it 

 may be seen to go beneath the water if the rock upon which it is run- 

 ning is partly submerged. 



LAMYCTES TIVIUS Chamberlin. 

 Ann. Ent. soc. America, 1911, 4, D. 33. 



DIAGNOSIS. Yellowish brown to dark brown, the last segments 

 and the first one mostly darker. Head dusky or blackish about eyes 

 and along suture with frontal region commonly paler. Legs yellow 

 to brown. Body slender; between eight and nine times longer than 

 the width of tenth plate; narrowed gradually from eighth plate cepha- 

 lad. Body nearly glabrous, the hairs being short and very sparse. 

 Head subcordate, slightly longer than wide. Antennae short; sub- 

 moniliform; articles 28, varying occasionally to 31. Prosternum cir. 

 1.68 times wider than long; teeth 3+3, the outer one each side small 

 and spiniform. None of dorsal plates with caudal angles produced. 

 Coxal pores small; 2, 3, 3, 3. Anal legs short; tibia 4.5 to 5.5 times 

 longer than thick; first tarsal joint cir. 8 times (rarely to only 7 

 times) longer than thick. Length 5-6.5 mm. 



DESCRIPTION. Dorsum yellowish brown to very dark brown, with 

 the anterior and posterior segments darker as usual, dusky in the 

 darker individuals. Often a more or less irregular dusky median band 

 showing especially on the more anterior and more posterior segments, 

 the borders of which are also sometimes darker. Head blackish about 

 eyes and along suture, with the frontal region often distinctly paler. 



