30 THE ENTOMOLOGIST S RECORD. 



as compared say with Hadena chenopodii or Ciccullia : the abdo- 

 minal segments tapering, 5th and 6th being as usual free ; 

 length 19 mm., width 5 mm., no hairs or bristles, though the 

 double hairs at the antennal bases exist in little more than 

 microscopic form. The sculpturing is in the form of very 

 minute pits, which are most numerous dorsally, and do not 

 exist on the leg and wing cases or thorax, which are finely 

 wrinkled, but not so as to interfere with the shining polished 

 character. The transparency permits, especially on the abdo- 

 minal segments, certain markings due to the interior structure 

 to be seen, and including a darker dorsal line (dorsal vessel ?) 

 a paler lateral one, with darker ^nd lighter (fat masses ?) 

 marbling between, the ventral aspect being paler. The pro- 

 thoracic spiracle is a very slender slit, almost obsolete, indeed 

 I am inclined to say that no aperture exists, those of the 2nd 

 to 7th abdominal segments each being marked, being raised on 

 a slight conical projection followed by a depression. The 8th 

 abdominal spiracle is visible but obsolete. The anal armature 

 consists of a wrinkled projection of the dorsal half of the 

 extremity, armed dorsally by two central spines, and ventrally 

 by three similar spines on either side. All this group have a 

 similar armature, but vary, especially in the number of ventral 

 spines on either side and in the curvature of the hooks, which 

 they often form or terminate in. In tridens there is a very 

 slight curvature, and the hold taken of the silk of the cocoon is 

 slight. In tridens their number is very usually three, but a 

 considerable proportion of pupae have four, or, not unfre- 

 quently, four on one side only. When this occurs, the extra 

 spine is often very slender and close to the outer side of the 

 outer one, as if split off" it. It is curious that the name tridens, 

 given no doubt on account of the trident or psi (Y^) mark of the 

 imago, should be so applicable to this typical point in the 

 pupal structure. The curvature of the ventral set is inwards, 

 of the dorsal pair downwards (ventrally) more decidedly than 

 the others (see PI. III., 2a, zb, 2d). Certain flattenings of the 

 dorsal surfaces of the first four abdominal segments, which are 

 more evident in some other species, are easily observed in this 

 species when carefully looked for. 



To form its cocoon this species appears to prefer to get 

 behind a piece of loose bark or into a chink of rotten wood, 

 where it hollows out a suitable cavity, which it completes into 

 a cocoon with some white silk and the removed chips, very 

 slightly, if at all, lining the excavated hollow. It will, however, 



