BY U. J. TILLYAKD. 599 



thick short hairs on the outer border are less regular ; and the 

 median lobe of the nientum is less indented and a little less 

 prominent. 



JInh. — Rocky Creek, Caroda, N.S.W. Taken December 

 14th, 1910. 



Larval Type and co-types in my collection. 



Tlie Structure of the Larval Gizzard. 



I have examined the gizzard of the larvae of both species, 

 and, as might be expected, there is very little difference. The 

 dentition is arranged in sixteen fields or folds, eight of these 

 being "major" folds and eight "minor." The gizzard of D. 

 lestohhs shews considerably greater regularity in the number 

 of teeth on a fold than does that of D. nipnphn'ides. Each 

 fold is of considerable length, about 1 mm. in actual size, so 

 that, in a "minor" fold, the teeth lie in a single longitudinal 

 line, while, in a "major" fold, the teeth (a greater number) 

 lie also in a longitudinal line, with a tendency to forming two 

 lines at the upper end. In the gizzard of D. lest old es, the 

 major folds each contained 11-12 teeth, the minor 8-9. In 

 that of D. nympho'ides, the major folds contained from 11-14- 

 and the minor from 4-7, with one minor fold containing 8 

 teeth, and one very tiny extra tooth. Representing these tiny 

 extra teeth by \, the teeth in this gizzard, taking the folds 

 in order, were 7, 11, 8^,, 12, 7, 13, 6, 11, 5, 11, 4, Uh, 5, 

 13, 4, 11. In D. lesto'ides, I noticed several isolated teeth 

 lying low down outside the main folds; as many as three of these 

 lay between two consecutive folds (see figure). In D. vym- 

 jih Okies, I found only one isolated tooth in the whole gizzard. 

 By comparing the figures given of one-half of each of the 

 above gizzards, the greater irregularity of that of D. nym- 

 phoTdes is very evident. I should not like, however, to sug- 

 gest that this difference is specifically constant, as I have 

 examined only one gizzard of each species. Bearing in mind 

 tne extraordinary difference in the number of teeth in the 



