NOTES TOWARDS A LIFE-HISTORY OF POLYOMMATUS DONZELII. 15 



body is still more thickly covered with small seta-bearing tubercles, 

 intermixed with minute lenticles which are' very irregularly placed. 

 The larger tubercles show scarcely any trace of the black apical ring, 

 which, however, can still be observed on the smaller ones. On the other 

 hand, they exhibit a double circle of spicules, one close to the apex, the 

 second midway to the base. The smaller tubercles are usually only 

 slightly spiculate at the base. The dorsal ridges are occupied by six 

 large tubercles, of which two are situated close to the dorsal stripe, the 

 remaining four forming a species of four-sided figure somewhat lateral 

 to the first two; interspersed among these are numerous smaller tubercles 

 in no special order. Between these and the supraspiracular tubercles, the 

 surface of the body is fairly thickly covered with numerous small 

 tubercles with very short seta?. The large lenticle of the previous 

 stages has been replaced by two very small ones, situated rather more 

 to the rear than was the case previously. In the supraspiracular area, 

 on the white field occurring below the second reddish stripe, are two 

 large anterior tubercles, and two smaller posterior ones, while the 

 lenticles of the previous instar have increased in number, although 

 diminishing in size, two or three occurring on the anterior margin, 

 while, posterior to the spiracle, is a group of three or four quite close 

 together. The customary small tubercles occupy the intervening 

 space. The arrangement on the flange shows practically no alteration 

 from that of the previous stage. The dorsal portion of the 7th 

 abdominal segment strikes the eye at once, owing to the absence of any 

 of the ordinary tubercles, and to the large increase in the number of 

 small tubercles and lenticles situated on the rear margin of the circular 

 depression already mentioned in the second instar. These, for the 

 most part lenticles, form a semi-circle across the posterior portion of 

 the segment, the anterior portion of the depression being fringed with 

 small tubercles, more widely removed from each other. On the 

 8th abdominal segment, the gland which had already begun 

 to develop in the previous instar, is now very marked, and capable of 

 being protruded like the finger of a glove, forming a white bell-shaped 

 structure, the upper margin of which is irregular, slightly hollow, and 

 with seemingly a central slit. While under observation, this gland 

 was in constant activity, swelling out and then collapsing together 

 again until only a faint white spot remained to mark its location. No 

 trace of any liquid exuding could be seen. The prothoracic plate is 

 small, and situated in a deep depression, which appears to be formed 

 b} r the continuation of the spiracular flange around the anterior portion 

 of the segment. The plate itself contains about 20 small tubercles and 

 lenticles, the two tubercles at the rear being larger and provided with 

 longer hairs. 



Fourth instar. — Length, when at rest, 7mm. Breadth, 2-5mm. 

 Shape, quite Lycsenid, with very flat posterior segments and broad 

 overhanging prothorax. The general appearance and markings are 

 very similar to those of the previous instar. The ground colour is a 

 very dull olive, the dorsal and lateral stripes have faded to a deep 

 olive, the former being slightly the darker, and the spiracular flange is 

 still reddish, with whitish outer margin. The position of the lateral 

 stripes is as before, only the first stripe shows a tendency to spread 

 downward on the posterior margin, while the third is much clearer, 

 the colour not suffusing with that of the flange. The segmental 



