ORTHEZIA INSIGNIS. 237 



laterally connected lamellae, which, after the first three 

 on each side, are directed backwards and downwards, 

 gradually increasing in length, the posterior ones over- 

 hanging the marsupium ; but of these the middle three 

 are shorter and more distinct, the median one, over the 

 middle channel, shortest and broadest of all, either 

 turned up vertically or horizontal, and having a median 

 sulcation ; the dark surface of the body level, nude, the 

 segmentation plainly discernible, but on the middle are 

 two longitudinal, narrow, contiguous yet distinct lines 

 of small, granulose, white, lamellate projections. These 

 lines, beginning at the base of each antenna, extend 

 backward for a short distance convergently, but almost 

 immediately after each curves outward and again 

 inward, so as to leave a small, dark, oval space between 

 them ; then both are parallel, and close together up to 

 the anal extremity. Marsupium snow-white, varying 

 in length, margins straight, parallel ; the upper side 

 shorter than the lower, longitudinally canaliculate, the 

 median channel wide, two others on each side of it 

 very narrow, and further down on the rounded sides 

 are usually slight striate indications of one or two 

 more channels ; underside shining, semi-tubular, being 

 transversely very arched, smooth, with the faintest 

 traces of transverse indications of the progressive 

 stages of development; posteriorly curved upward, 

 apex truncate, but the lateral angles produced " 

 (Douglas, 1. c.). Denuded female, after treatment with 

 potash, ovate, slightly narrowed in front, widely 

 rounded posteriorly. Gland-tracts corresponding in 

 position to the external cereous plates ; glandiferous 

 spines very slightly curved, bluntly pointed, and 

 suddenly dilated at the base. Eyes comparatively 

 small, hemispherical. Antennae (fig. 16) spinose, of 

 eight joints; formula 8 (3, 1) (2, 3, 4, 5), 6; apical 

 spine strong, bluntly pointed. Mentum biarticulate ; 

 basal joint scarcely one-third the length of the apical 

 joint; apex of the latter with several rather long 

 spines; legs rather strongly and closely spinose, 



