97 



common base, basal segment large and swollen, bearing an ex- 

 tero-lateral prolongation which somewhat resembles in size and 

 appearance the small cylindrical 2nd and minnte papilliform 

 3rd segments. 



Thorax. — The thoracic segments are mnch coalesced and ill- 

 defined ; the ventral tnbercles of the 1st approximate to the 

 month, folding aroimd the latter; dorsally this segment bears 

 a pair of small papilliform stigmata, the ventral tubercles of 2na 

 and 3rd segments are well-developed and bear numerous setfe 

 and booklets. 



Abdomen. — A slight constriction separates the thoracic and 

 abdominal regions, the latter consists of 9 segments, many of the 

 ventral tubercles are so well developed as to function as pseudo- 

 pods. lst-5th segments, pseudopods well developed, bearing nu- 

 merous seta? and booklets; Gth-Tth segments, pseudopods and 

 booklets less developed ; 8th segment bears a pair of small, point- 

 ed ventral and two pairs of large lateral pointed tubercles, pseu- 

 dopods absent. 9th segment bears a pair of lateral pointed tuber- 

 cles and is terminated by the strongly chitinized stigmatie tubes. 



Puparium. — 6 x 3 mm., dark, dull testaceous, thoracic stig- 

 matie tubes shining testaceous one-eighth the total length of pu- 

 parium, apices rather swollen. Posterior stigmatie tubes shining* 

 testaceous one-sixth total length, apex fringed. The three pairs 

 of postero-lateral tubercles distinctly visible, as in the larva. 

 The puparium bears a strong general resemblance to that of 

 Voliicella ohesa but both thoracic and posterior stig-matic tubes 

 are much longer relatively in Syritta. 



The various stages in the life-history of this fly are figured 

 on Plate 4, as below : 



Fig. 5. Egg of Syritta occanica ^facq. — x 100. 



Fig. G. Portion of chorion showing thickened areas of the 

 membrane. — x 400. 



Fig. 7. Adult larva of S. ocean ica (dorsal view) ; a, thoracic 

 stigma ; b, antenna ; c, posterior stigmatie tube. 



Fig. <S. Anterior extremity of larva (ventral view) : a, basal 

 antennal segment; a\ lateral process of same; 

 a-, 2nd antennal segment ; a"^, minute 3rd seg- 

 ment ; b, buccal cavity; c, 1st thoracic pseudo- 

 pod ; d, 2nd thoracic pseudopod. — x 30. 



Fig. 9. Puparium ; a. thoracic stigmatie tube. — x 12. 



