On Two new Spiders from Demerara. 139 
XVII.—Deseription of Two new Spiders obtained by Messrs. 
J. J. Quelch and B. McConnell on the Summit of Mount 
Roraima, in Demerara ; with a Note upon the Systematic 
Position of the Genus Desis. By R. I. Pocock, of the 
British Museum. 
MYGALOMORPH &, Poc. 
Family Theraphoside, Thor. 
Subfamily Baryczerivz, Sim. 
Genus CYRTOGRAMMOMMA, nov. 
This genus is most nearly related to Ldiophthalma of 
Cambridge. ‘The characters of the two may be contrasted as 
follows :— 
IDIOPHTHALMA.—Posterior row of eyes much wider than 
anterior row (nearly. twice as wide), distance between anterior 
lateral eyes about twice a diameter. 
Cephalothoracic fovea strongly procurved (teste Simon; the 
type in the British Museum of J. suspectum, Cambr., has 
been pinned through this spot). 
Mandibular rake formed of a single transverse series of 
shortish spiniform teeth. 
Labium without teeth ; maxille with only two teeth. 
Legs short and robust. 
CYRTOGRAMMOMMA.—Posterior row of eyes only slightly 
wider than anterior; distance between anterior laterals about 
four times a diameter. 
Cephalothoracic fovea strong and straight. 
Mandibular rake merely represented by a few spiniform 
sete, which are only a little stouter than the normal sete 
which clothe the rest of the mandible. 
Labium wider than long, almost unarmed, furnished with 
3 spinules ; maxillz furnished with a small cluster of irregu- 
larly arranged spinules. 
Sternum circular, with marginal impressions. 
Legs longer and thinner. 
Cyrtogrammomma monticola, sp. n. 
Colour a uniform coffee-brown. 
The entire body covered with a clothing of short hairs. 
Carapace high, oval, much longer than wide, the length 
equal to the patella and tibia of the first leg, the width to the 
