Quail. — On Ntiv Zealand Lepidoptera. 161 



are not retained in the imago. The spiracles (breath- 

 ing-organs) are lateral, one each side of the prothorax and 

 first eight abdominal segments ; those of the prothorax and 

 8th abdominal segments are often larger than the spiracles of 

 any other segment. The absence of spiracles from meso- and 

 post-thoracic segments may be associated with the ultimate 

 development of the imaginal wings. 



The thoracic and abdominal segments are made up of 

 minor subsegments, and the skin is frequently covered wholly 

 or in part (figs. 12-11) with minute hairs, and in more or less 

 fixed position there are certain pimples (termed " tubercles"), 

 which form the base of longer and stouter hairs (termed 

 "setae"). The position of the tubercle setae affords a basis 

 for classification. The arrangement of the tubercles of pro- 

 thorax is mostly scutellar — i.e., on the dorso-lateral plate or 

 scutelluin — and always differs from the arrangement of the 

 tubercles on meso- and post-thorax. 



[Since the above was written Dr. G. Harrison Dyar r 

 writing in the " Century " number, vol. xiii., " Entomologists' 

 Kecord," states : " I now agree with Dr. Hofmann that the 

 thoracic and abdominal setae are homologous," a conclusion 

 reached by the present writer independently but not stated, 

 as hitherto Dr. Dyar had not formed that opinion. The 

 nomenclature of the thoracic (below the scutellum) and ab- 

 dominal setae should correspond.] 



I have noted elsewhere" a probable generic distinction 

 among Hepialidce (Porina and Charagia) in the arrangement 

 of the prothoracic scutellar setae, and have noticed consider- 

 able diversity in the position of the prothoracic tubercles in 

 most groups of Lepidoptera. The more fixed position of the 

 abdominal tubercles appears to be of little value in differen- 

 tiating genera, though of great significance in classifying larger 

 groups. 



The arrangement of the meso- and post-thoracic tubercles 

 differs frorn the abdominal, though more approximate than 

 those of the prothorax ; the abdominal segments are practi- 

 cally duplicates — except 9 and 10, which are always modified. 

 Newly hatched larvae usually have the primitive arrangement 

 of tubercles in the group of which they are representative, 

 and also usually have primitive tubercles with single setae. 

 Multiplication of tubercles (and reduction) and of setae takes, 

 place after the first moult, though sometimes newly hatched 

 larvae exhibit specialisation. 



Abdominal "dorsal tubercles : On the back four tubercles 

 are placed, as it were, at the corners of a trapezoidal figure, 

 those in front being near each other, those behind being more 



* TraLS. Eut. Soc. London, 1900, p. 424. 

 11 



