COCHLIDION AVELLANA. 371 



Larva. — The newly -hatched larva is spiny, somewhat elongated, 

 and not Chiton-sha,ipe& (Burrows) ; whitish, stout, with a small black 

 head (Horton). Chapman says that in it the ordinary tubercles can 

 be made out as very faint dots, and, in addition, there are a number 

 of evaginated, spurred spines, three on each side of the thoracic, and 

 two on the abdominal, segments, the latter arranged as a dorsal and 

 lateral series on either side. The dorsal series is placed alternately 

 on the segments .-.•.-., outer on the first abdominal, inner on the 

 second, and so on ; this arrangement has suggested to Chapman that 

 they are homologous with alternate members of the double dorsal 

 series of structures present in the larva of Micropteryx (mite, p. 138). 

 After the first moult the spines become smooth and straight. The 

 larva is now 1*4 mm. in length, and carries its cast skin, with some 

 frass, on the terminal spines (? like Adscitid larva). The two 

 dorsal rows of spines are now double, i.e., the alternate members, 

 absent in the first skin, are now developed, each spine consisting of a 

 pointed hair-like process, but with an internal tubular structure that 

 differentiates it from a real hair, although the terminal portion may 

 be homologous with the hairs carried by ordinary tubercles. On the 

 mesothorax the spines are more equally distributed ; on the metathorax 

 they are a little larger than on those following, but have the same dis- 

 tribution. This is such that the back of the larva forms a hollow groove, 

 bounded on each segment by a double tubercular spine rising on either 

 side, which are alternately (on consecutive segments), rather nearer and 

 further from the middle line, those on the 3rd and 5th abdominals being 

 notably further out. On these (3 and 5 abdls.) the outer spines are very 

 large and project more laterally. This double tubercle consists really of 

 an inner and outer process, each bearing a spine, the inner one being 

 rather the larger. The spines are without any evident processes or hairs, 

 but their terminal third (or fourth) is dark in colour, and apparently 

 articulated to the basal portion, which is pale and nearly colourless, 

 except for the articulation of the terminal portion, which looks brittle. 

 The whole spine looks very like a nettle sting, and seems to be 

 tubular. On the outer margin of these tubercles are several very 

 minute spinules or hairs, as well as some thicker and apparently 

 capitate ones in the lateral region. The true legs are minute, and the 

 spinneret quite distinct. After the second moult, the larva is 3 mm. 

 long and 2 mm. wide. The arrangement of the spines is much as in 

 the previous skin, but small spinules now surround the bases of the 

 others, and whilst the spines proper are simple, the spinules have 

 coroneted apices. The dorsal humps are large, and consist of an inner 

 and outer spine, which are simple, but on the tubercular structures at 

 their inner and outer bases the points that stud the general sur- 

 face are more crowded. The lateral humps are single, but have a 

 more complex structure. The pyramidal base looks three-jointed, and 

 carries subsidiary transparent spines with divided points, like those on 

 spines of the newly-hatched larva, but a little less elaborate. Some 

 appear to belong to each joint. The terminal spine has a jointed apex, 

 like the dorsal ones, and the basal portion looks as if articulated to the 

 tubercles, but this is possibly a deceptive appearance. In the incisions 

 at the bottom of the dorsal and lateral grooves are yellow islets, 

 probably belonging to the anterior segment, but apparently belonging 

 to neither, The humps and subcutaneous space look quite glassy, the 



