148 JOURNAL OF ENTOMOLOGY AND ZOOLOGY 



miicrones over twice the lengtli of the manubrium; dentes ser- 

 rated ou botli edges ; mucro bidenticuhite, distal tootli is sUghtly 

 curved and ahout tlie same length as the proximal one which 

 is curved slightly ('('i)lialad, the axes of the two teeth almost 

 parallel. Integument — Sparsely covered with short hairs. 



Varialion: The markings in this species are not at all 

 regular and the color varies considerably with the yellow and 

 brown predominating in some and the blue in others. There 

 was a variation in the superior claw as mentioned above; how- 

 ever, there was no variation among the specimens in each 

 locality. 



Ildhifat: They were found in great abundance on pools of 

 water in a newly plowed field after a hard rain ; they were asso- 

 ciated with a new species of Xenylla. Also I found them in 

 San Antonio Canyon at Camp Baldy under rocks, and in the 

 (Janesha Hills under the same condition, but they were not very 

 abundant in either of these localities. Also they were found in 

 San Dimas and Lytle Creek canyons. 



Isotoma hesselsii Packard 



(Plate I, Fig. 10) 



Isotoma hesselsii Packard, 1877. Explorations of the Polaris 

 Expedition to North Pole. Amer. nat. XI, 51-53. Packard, 

 1877, Amer. nat., p. 51-52 (footnote). MacGillivray, Can. ent. 

 XXIII, p. 273. Davenport, 1903, Coll. of Cold Spring Beach, 

 Cold Spring Harbor, mon. II. 1905 (Axelson) Linnanienii 

 zur Kennt. der Aptery., vol. 7, viir. Bacon, P. C. jr. ent. and 

 zooL, vol. IV, pp. 843-845. 



Description: In general a])]iearance they look almost exactly 

 like the 7. hidenticula , although slightly smaller. Length — .75-1. 

 mm. Color — Brown, yellow at junction of segments ; furcula and 

 legs light; ventral side dark. Antennas — About as long as head; 

 I shortest, IV longest, II and III subequal. Ocelli — Sixteen, 

 (laws — Slightly curved; superior wide at the base Init narrow 

 at the apex; inferior with inner margin dilated at the base. 

 Furcula — Short, stout, not reaching ventral tubes; manubrium 

 slightly longer than dentes; nmcro tridenticulate; distal tooth 



