154 MEDICAL ZOOLOGY. 



often of eleven articles. (Regne Animal.) These insects vary very mucvm 

 form ; some of them are oval and slightly convex scales, and others have the 

 shape of a muscle; some are quite convex, and either formed like a boat 

 turned bottom upwards, or are kidney-shaped, or globular. 



Measurements. l'"-l'" in length. 



Habitat. They live mostly upon the bark of the stems of plants ; some, 

 however, are habitually found under leaves, and some on roots. The supply 

 for commercial purposes is received from Mexico. Specimens have been 

 seen on Opuntia in Nevada, by Mr. Wm. M. Gabb, and in Idaho by Lt.-Col. 

 A. W. Bowman, U. S. A. 



Species mentioned in connection with medicine: (7. cacti; C.illicis; C. 

 lacca. (Moquin-Tandon.) 



APIS. Hymenoptera. Neuter. Body nearly cylindrical, and subpubescent. 

 Head transverse, about as wide as the thorax ; vertex and face deeply longi- 

 tudinally channeled in the centre ; the ocelli rather large ; compound eyes 

 very pubescent; antennae short, filiform, geniculated ; the scape (basal joint) 

 nearly half the length of the flagcllum (remaining joints), and subfusiform ; 

 clypeus (piece behind labrum) quadrate, convex; labrum transverse, linear, 

 slightly waved in front; mandibles broad at apex ; cibarial apparatus short- 

 ish; tongue nearly twice the length of the labrum, linear, pubescent, and 

 terminating in a small knob ; labial palpi not quite so long as tongue ; max- 

 illae broad, hastate (triangular); maxillary palpi extremely short, the basal 

 one the shortest. Thorax subglobose ; prothorax inconspicuous; metathorax 

 truncated ; legs slender, subpilose ; the anterior and intermediate tibia3 with 

 a spur; their plantae (under surface of first tarsal joint) with a dense short 

 close brush all round ; the posterior tibia3 triangular, glabrous within, extern- 

 ally smooth, shining, and irregularly concave,* the edges fringed longitudinally 

 with long hair curving inwards, and forming the sides of the corbiculum (re- 

 ceptacle), which conveys the material of the nest; the apex transverse and 

 pectinated with short rigid setae, but wholly without spurs ; the plants oblong, 

 not quite as long as the tibiae, the sides nearly parallel, the upper edge fringed 

 with long, loose hair, subglabrous externally, but furnished internally with 

 ten transverse parallel rows of short hair ; the remainder of the tarsal 

 joints short, the fourth the shortest, and the claw-joint the longest ; the claws 

 short, robust, and bifid. Abdomen retuse (obliquely truncate at base), sub- 

 cylindrical, convex above, and terminating conically, the first segment very 

 short, the second the longest, the ventral segments rigid longitudinally in the 

 centre. 



Female (Queen) head not so wide as thorax, in having the cibarial appa- 

 ratus very much shorter ; the mandibles distinctly bidentate, the inner edge 

 of the inner tooth stretching obliquely to the acute inner extremity of the 

 broad apex of the organ ; the labial palpi as long as the tongue, with all the 

 joints conterminous, the basal one slightly acuminate, the second linear, 

 the two terminal ones more slender and shorter, the pubescence of the eyes 

 very much longer than in the neuter; the legs more robust and less pilose; 



