ARTHROPODA OF THE COMMANDER ISLANDS. 349 



length of the joint, whole palpus with a few scattered hairs, rather longer than the 

 width of the joints; legs moderately long, and with scattered hairs. Length, 1.3 mm. 



Ty:pe.—No. 4036, U. S. N. M. 



Several specimens from Bering Island, July- August, 1897 (Dr. Stejneger). Differs 

 from B. mllosd in smaller size, more slender mandibles, and in the shorter fourth joint 

 of the palpus. 



Family GAMASID^. 



(13) Holoataspis arcUcus KBamei and Neumann. 



Gamasug aroUcua, ibid, Aoariden wahrend der Vega Expedition eingesammelt, p. 528. 

 Several specimens from Bering Island, July-August, 1897 (Mr. Barrett-Hamilton); 

 two from Grlinka, Copper Island, August, 1897 (Dr. Stejneger). Described from 

 Bering Island. 



Family IXODID^. 



(14) Ixodes horeaUs Kramer and Neumann. Aoariden wahrend der Vega Expedition eingesammelt, 



p. 526. 



Several specimens ftom Bering Island, July- August, 1897 (Dr. .Stejneger). 

 Described from this island. Ixodes fimbriatus, of the same authors and from the 

 same locality, is probably the male of this species. Dr. Stejneger also took a specimen 

 on Toporkoff Island. 



Family ORIBATID^. 



(15) Oribatella borealis, new species. Plate A, fig. 2. 



Black; a pale triangular spot at base of the abdomen; wings, tectal plate, and 

 legs yellowish. Tectal plate large, covering the whole of the cephalothorax, deeply 

 cleft, each side truncate at tip; two superior bristles; setae moderately short, clavate, 

 dorsum of abdomen with a few fine short hairs (inconspicuous) ; wing large, in front 

 at base with a slender, curved, acute projection, reaching forward as far as tip of the 

 head, below the wing is rolled in, but from below shows a nearly square corner at 

 the tip; venter smooth; the genital opening is in the form of a trapezium, more than 

 twice its length in front of the larger anal opening; coxal plate shows only two short 

 lines each sidLi; legs short, the femora rather broad. Length, 0.5 mm. 



Two specimens, Glinka, Copper Island, August, 1897 (Dr. Stejneger), 



Type.— Ho. 4057, U. S. F. M. * 



(16) Oppia aretica, new species. Plate A, flg. 6. 



Black ; legs paler. Body rather short and broad ; tectal plate free at tip, two- 

 pointed, each with a short bristle; at base are two very long and erect superior 

 bristles; setae of moderate length, broadest toward tip, but the tip pointed; tecto- 

 podium of first legs large and prominent; legs rather short, with simple hairs, the 

 femora not very broad; abdomen smooth, with a few hairs at tip above, and some on 

 . the venter toward tip; genital opening fully twice its length in front of the larger 

 anal opening; sternal plate shows complete transverse lines. Length, 0.8 mm. ,., 

 Type.— So. 4058, U. S. N. M. » 



One specimen from Glinka, Copper Island, August, 1897 (Dr. Stejneger). 



(17) Bermannia quadriseriata, new species. Plate A, flg. 4. 



Black; hairs white; legs red-brown. Abdomen elliptical, dorsal surface reticulate 

 above, with four rows of six slightly clavate hairs; cephalothorax triangular, with a 



