54 BULLETIN OF THE ESSEX INSTITUTE. 



Postaiitennal organ :ibsent. Antennae subequal to the 

 head, in length, with segments in relative lengths as 7 : 

 8:9: 9 ; basal segment stout, globose or compressed 

 (Fig. 12); second, swollen apically ; third, more slen- 

 der, cylindrical; terminal segment conical. Body cylin- 

 drical-ovate, the abdomen being much dilated laterally ; 

 the segments, measured along the median dorsal line, are 

 related in length as 4 : 6 : 6 : 7 : 7 : 6 : 9 : 6 : 3 ; the 

 head and body are clothed with minute bristles, inter- 

 spersed with a few longer setse. Legs stout ; tibiae 

 (Fig. 13) with two, minutely-knobbed, tenent hairs; 

 feet uniunguiculate ; claw stout, uniformly tapering, 

 slightly curved and untoothed ; inferior claw represented 

 by the merest rudiment, Furcula (Fig. 14) extending 

 considerably beyond the abdomen ; manubrium triangu- 

 lar ; denies tapering, each with two setse ; mucrones one- 

 third longer than the dentes, clearly articulated with the 

 latter, very slender, gradually tapering to a minute point. 

 Anal spines and papillse are quite absent. 



Length 1.4 nmi. Described from forty-two types, 

 which Dr. Goto found " between the scales of old pine- 

 cones, June 24, 1897." 



X. longicauda is decidedly unlike any hitherto described 

 species of Xenylla, but is nearest related to X. humicola 

 O. Fabr. (1780, p. 213-214, Podura humicola). X, 

 longicauda, as contrasted with this near ally, has a fur- 

 cula which is relatively much longer and much more 

 slender, also mucrones which considerably exceed the 

 dentes in length ; moreover theie are no traces of anal 

 spines or papillae, which, although reduced in certain 

 species, nevertheless occur in all other known species of 

 Xenylla. 1 



» For descriptions and figures of X. humicola, consult O. Fabriclus 1780, p.213- 

 2U; Tullbert? '70, p. 39, tal'. X, flgs. 44-46; Rcuter '95, p. 32, tab. 2, fig. 10; and 

 Schaffer '96, p. 169-170, taf. 2, lig. 43. 



