76 [April, 



obsolete; their position is indicated by a couple of truncate spines, and within them 

 a group of, usually, four compound spinnerets. Long., 2 — 275 mm. 



? , 2nd stage, more elongate than the adult, but in other respects it scarcely 

 differs. 



<J dark crimson ; has two very long white caudal filaments. Antennae (fig. 4, 

 4th and oth joint) of 10 joints, of these the 1st is the shortest; all, with the 

 exception of the Ist, with several large, tuberculate, spines ; joints 5 — 10 with two 

 to three long, slender, knobbed hairs ; last joint (fig. 2) with three long stout spines, 

 in addition to the smaller ones. Legs with a two-jointed tarsus ; the articulation 

 of which is clearly visible when the tarsus is bent slightly upwards (fig. 5), but 

 when it is curved inwards the joint appears as a narrow raised ring of chitine 

 (fig. 6), and apparently fused. 



Larva elliptical ; colour dark crimson. Legs very long ; digitules ordinary. 

 Antennffi (fig. 7) of six joints. Mentum monomerous ; unexpanded filaments much 

 longer than the body. Anal orifice as in the adult ? . Dorsum with three longi- 

 tudinal rows of truncate spines ; and there are spines of the same character at the 

 margin. 



Hah. : lioyal Gardens, Kew ; on Opunfia fulgida, recently im- 

 ported from Arizona. At the time of my visit the adult $ were 

 nearly all dead ; but there were quantities of them, as also of the 

 immature ? ; and I was fortunate in rearing half a dozen ,^ . The 

 larvae simply swarmed, and were actively engaged passing up and 

 down the long barbed spines of the food-plant, evidently enjoying the 

 intense heat of the mid-day sun. 



The constancy of G-jointed antennae, and the comparatively small 

 size of the $ is very marked ; for this reason I at first considered my 

 examples as a distinct and undescribed var. Now, thanks to Mr. 

 Cockerell, I have been able to examine a long series of C. tovientosus, 

 which were collected by Dr. Duges in Mexico, and find the number of 

 antennal joints to vary ; usually there are 7, but 6 joints are not 

 infrequent ; and small adult ? containing well formed larvae are not 

 rare, but the average size of the Mexican examples is much larger than 

 the British. 



C. confusits, Ckll., differs from the above, only, in having much 

 larger groups of compound spinnerets, and longer truncate spines. Of 

 the former those near the margin of abdominal segments are the 

 largest, and consist of about 50 to 90 spinnerets, or more. 



It may be couTenient here to add that the cochineal of commerce 

 (C. cttcfi, Lin., Sign , $ ) may be recognised from either of the above by 

 its much larger size, and the total absence of dermal truncate spines. 

 Signoret (Essai, p. 381) makes no mention of these latter, and I am 

 therefore of opinion that that author had the same species under 

 observation as myself. 



