120 Proceedings of the Royal Physical Society. 
feet. Careful search below the former altitude produced no examples, whilst 
above the latter the ground was covered with snow. Most of the specimens 
were found under stones on bare patches of ground surrounded by masses of 
snow. During the major part of the year the species, together with other 
spiders occurring in the same place, must be completely snowed up. The 
inferior height and extremely graceful and pointed summit of Schiehallion 
renders that mountain not so favourable to the accumulation of thick deposits 
of snow. 
Robertus scoticus sp. nov. 
[Plate II. Fig. 15.] 
FEMALE.—Total length, 2 mm.; cephalothorax, ‘84 mm. 
Carapace.—Dark yellow-brown. Traces of a darker marking at the 
thoracic juncture, with radiating lines present. 
EHyes.—In two rows. 
Anterior row straight. Centrals by far the smallest and darkest. 
Centrals almost in contact much less than a diameter from 
laterals. 
Posterior row straight, or very slightly curved, with convexity behind. 
Centrals slightly less than laterals. All eyes about a diameter 
apart. Ocular area much pigmented. 
Clypeus.—Dark yellow-brown, about as high as ocular area. In profile 
the thoracic juncture is very distinctly the highest part. Thence the dorsum 
slopes down evenly and gradually to the ocular area, which is not at all 
prominent. Backwards the dorsum slopes down rapidly to the peduncle ina 
curve concave behind. 
Sternum.—Heart-shaped, yellow-brown, ornamented with dark brown 
streaks. Termination not passing the last coxe. 
Labium and maxille.—Dark yellow-brown. 
Palpus.—Y ellow-brown, darker on the last two articles. Tarsus clawed. 
Legs.—Yellow-brown, with tarsi and metatarsi darker. 
Abdomen.—Yellow-brown, much suffused with brown pigment above. 
This is arranged in a somewhat reticular pattern, enclosing many small round 
spaces which show the lighter ground colour; below more irregularly 
pigmented. 
Book-leaf trachea.—Pale yellow-brown, each bordered by a darkly pig- 
mented zone. 
Spinners.—Pale yellow-brown. 
Epigyne—Highly characteristic. Sexual aperture placed near the 
