258 



In general appearance the two species described below are 

 6trikingly like several species of Thorictus of the Clavicornes ; 

 but the tarsi are heteromerous, tibiae very different, and 

 prosternum without pads of clothing. I carefully examined 

 the type of each species both from above and below without 

 seeing eyes, and then decapitated them and examined the 

 heads under the microscope from many angles still without 

 seeing any, so presume both species to be blind. Most of the 

 surface under a fairly high power of the microscope appears 

 to be very finely granulate or shagreened, and in certain 

 lights this causes some parts to have a deceptive resemblance 

 to eyes, but when viewed at a right angle this resemblance 

 vanishes. The clypeus and labrum appear to be absent, • as 

 there are no sutures defining their margins. The mentum is 

 large and convex, concealing the labial palpi; of the maxillary 

 palpi only the two apical joints (these fairly stout and sub- 

 equal) are visible. The antennae are eleven-jointed, but the 

 joints are so close together arid even in width at their junctions 

 that it is only under a fairly high power that they can be 

 counted; the three basal joints are concealed from above, the 

 three apical ones form a closely compacted club. The fovea on 

 each of the front angles of the prosternum is closed externally, 

 but open internally, it is evidently for the reception of the 

 club of the antennae, the basal portion of which is received, 

 when at rest, within a groove (bounded internally by a strong 

 ridge) on the lower part of the head. Both species are gently 

 convex with oblong-elliptic outlines. The parts of the mouth of 

 inquilines are usually so greatly modified from species living 

 normal lives, that I do not regard the great modifications of 

 these as excluding the genus from the Tenehrionidae: In 

 catalogues it may be placed near Typhluloma, the only other 

 known blind genus of the family, but it differs from it in many 

 particulars of the head, antennae, and legs, in some respects 

 it appears to approach Brachycdibe and Plat ycil the, and with 

 the fossorial front legs of Caedius, Caediomov'pha, etc. Type 

 of genus, ectatommae.. 



Thouictosoma ectatommae, n. sp. 



Dark castaneous-brown, legs and antennae somewhat 

 paler. Glabrous. 



Head gently convex, with two vague oblique depressions 

 in front ; punctures dense and sharply defined but rather 

 small. ProtHqrax about once and one-third as wide as long, 

 front angles lightly produced but not clasping sides of head, 

 hind ones not quite rectangular; punctures much as on head, 

 but becoming more crowded on sides. Elytra about the width 



