36 BULLETIN 168, UNITED STATES NATIONAL MUSEUM 



short curving setae of uniform length (pi. 10, fig. 106), on the middle 

 regions of the body segments; long outstanding setae absent. Integ- 

 ument tuberculate. Length, 1.2 mm, 



Cotypes.—V.S.'NM. no. 42996. 



Distribution.— 'Recorded as follows: 



California: Palo Alto, V. L. Kellogg and L. Bremner. 



GUTHRIELLA MUSKEGIS (Guthrie) 



Plate 11, Figures 107-112; Plate 12, Figures 113-119 



Isotoma muskegis Guthrie, 1903, p. 72. 

 Guthriella muskegis Borner, 1906, p. 172. 



Description. — A robust species (pi. 11, figs. 107, 108). Blue-black, 

 with small pigmentless spots dorsally. Tergites often edged pos- 

 teriorly with blackish. Tubercles and abdominal horns of the male 

 "light yellowish brown, giving to the body a yellow, floured appear- 

 ance to the naked eye." Antennae dark blue; legs pale, mottled with 

 blue, with dark coxae ; manubrium pigmented ; dentes white or slightly 

 pigmented. Eyes eight on each side, subequal, on black patches. 

 Postantennal organ (pi. 11, fig. 109) subelhptical, about as long as 

 the diameter of an eye, with a deep notch at the middle of the anterior 

 margin, and situated in a shallow groove at the base of the antenna. 

 Antennae about one and one-half times as long as the head ; first and 

 second segments subcylindrical ; tliird subclavate; fourth subelhptical 

 or subclavate. Sense organ of tliird antennal segment with two 

 linear feebly curving rods. Tibiotarsus with a distal subsegment 

 (pi. 11, fig. 110). Unguis (pi. 11, fig. 110) slender, without lateral 

 teeth, strongly unidentate near the middle of the inner margin. 

 Unguiculus extending one-half to three-fifths as far as the unguis, 

 longest on the hind feet, sublanceolate, acute or acuminate, untoothed, 

 with a pair of inner lamellae. Tenent hairs 2 or 3; commonly 2, 3, 3. 

 Abdominal segments without ankylosis. Furcula appended to the 

 fifth abdominal segment, extending to the ventral tube, stout. 

 Manubrium naked ventrally, with a pair of subapical hooks as in 

 antiqua. Dentes one-fifth longer than manubrium, bowed (pi. 11, 

 figs. 107, 108), convergent, not tapering, without dorsal crenulations, 

 with only the fine primary cuticular tubercles, and with a few setae 

 dorsally and ventrally, the latter on the distal half. Mucrones (pi. 

 11, figs. Ill, 112; pi. 12, figs. 113, 114) as long as hind ungues, biden- 

 tate, bilamellate; apical tooth hooked; outer and inner lamellae 

 similar, extending from the base of the mucro to the anteapical 

 tooth. Rami of tenaculum quadridcntate; corpus bisetose. Long 

 erect sensory setae absent. Integument finely tuberculate. Length, 

 2.5 mm. 



