496 PROCEEDINGS OF THE NATIONAL MUSEUM. tol. 50. 



XEmfLLA HUMICOLA (O. Fabricius) Tullberg. . 



Plate 17, figs, 137-142. 



Podura humicola O. Fabricius, 1780. 



Achorutcs humicola Lubbock, 1873. 



Xenylla humicola Tullberg, 1876.— MacGillivray, 1891.— Dalla Torre, 

 1895.— Reuter, 1895.— Schaffer, 1896, 19006.— Carpenter and Evans, 

 ]899.— Skorikow, 1900.— Wahlgren, 1900«, 19006.— Krausbauer, 1901.— 

 Agren, 1903.— Davenport, 1903.— Axelson, 1905, 1906.— (Axelson) 

 Linnaniemi, 1907, 1909, 1911, 1912. 



Xenylla maritima Meinert, 1896. 



Dark blue. Eyes five on each side (fig. 137). Antennae slightly 

 shorter than the head. Fourth antenna! segment with four or five 

 olfactory hairs three or four lateral and one dorsal. Unguis (fig. 

 138) curving, with inner margin unidentate one-third from apex. 

 Tenent hairs two, knobbed. Tenaculum tridentate on each branch. 

 Manubrium with a deep median-longitudinal ventral furrow. Dens 

 a little longer than mucro, with two dorsal setae (fig. 139). Mucro 

 clearly articulated with dens, slightly longer than hind unguis, 

 gradually tapering (figs. 140, 141), apically rounded, with a narrow 

 lamella terminating before the apex, and with a sharp ventral in- 

 cision about one- third from the base. Anal spines two (fig. 142), 

 minute, conical, straight, on minute papUlae separated from each 

 other. Clothing of sparse short curved setae, with a few longer 

 bristles, some of the larger setae being denticulate. Maximum 

 length, 1.5 mm. (2 mm., Schaffer). 



The North American specimens that I have studied happened to 

 be somewhat smaller than European examples, of which I have 

 received 27 from Doctor Schaffer, but agreed with them in every 

 other respect. 



Massachusetts. — Revere, August 23, abundant under A board on a 

 salt marsh. 



New York. — Cold Spring Harbor, Long Island, C. B. Davenport. 



Ontario, Canada. — St. Thomas, August; Toronto, December (Div. 

 Ent., Ottawa). 



XENYLLA BACONAE, new species. 

 Plate 18, figs. 143-149. 



Blackish blue; antennae, legs, and furcula violet. Eyes five on 

 each side. Antennae subequal to head in length. Sense-organ of 

 third antennal segment as in figure 143. Unguis (fig. 144) slender, 

 untoothcd. Tenent hairs two, laiobbed, extending almost to the 

 apex of the unguis. Furcula not extending to the apex of the 

 abdomen. Dens and mucro clearly demarcated by an articulation 

 (fig. 145). Dens with two dorsal setae. Mucro (fig. 146) four- 

 fifths as long as dens, subequal to hind unguis in length, gradually, 

 tapering, apically rounded, with a sharp ventral incision one-third 



