372 



Mr. F. W. Edwards on the 



♦luteipes, 46. 

 •maculiveiitris, 34. 



maindroni, 49. 

 ♦ruarginata, 31. 



melanoeephala, 39. 



ruelauura, KoUar ^ Redt,, 41. 

 *uilgirica, 26. 

 *iutida, 60. 



pallidicolor, 60. 

 *plectrophora, 1. 

 *rostrif'era, 48. 



rouyeri, 2^. 

 *seiwitecta, 38. 



terminata, 3. 

 *tnserrata, 16. 

 *uncio:era, 29. 

 *uiigulata, 12. 

 *variconiis, 54. 



*varipes, 66. 

 *virescens, 15. 



viridescens, 19. 



viridipennis, 17. 

 *vividivittata, 33. 



Synonyms and Varieties. 

 brevicoruis (Prionocerus), 1. 

 cajruleatus, 18. 

 cardoni, 44. 

 ce_ylonica, 39. 

 diversipennis, 25. 

 forticornia (Prionocerus), 1. 

 fuscipennis (Prionocerus), 1. 

 melanura, Muls. ^- Bourg., 40. 

 naetallescens, 19. 

 uotaticollis (Prionocerus), 2. 

 tripartita, 2. 



EXPLANATION OF PLATES XI. & XII. 



Figs. 1-49. Profile views of the S genital armature of species of 

 Priotiocertis and Idyia, one oulj' of the lateral lobes shown and the 

 free tubular median Icbe lowered from its normal position, so that 

 a clearer outline could be given of it, the apical portion of the sac 

 (when visible in the dried specimens) added; 9a and 10a, dorsal 

 views of 9 and 10, the median lobe omitted in 9 « ; 49 a, sixth 

 ventral segment of /. pallidicolor, cJ; 60, apices of elytra of 

 I. vncigera, $ ; all X 12. In tig. 46 the median lobe is out of its 

 normal position, and shown from the ventral aspect. 



XXXIV. — A Note on the Egg-burster of Eucephalous 

 Fly-larvcs. By F. W. Edwards. 



In widely separated divisions of the animal kingdom special 

 embr3'ouic organs are found whose function is to facilitate 

 the hatching of the embryo from the egg. Eieryone is 

 familiar with the hard knob which occurs on the tip of the 

 upper jaw in the chick as well as in other oviparous 

 vertebrates. Among the Insecta egg-bursting organs are 

 often found on the dorsal surface of the head, and assume 

 a variety of forms. Different types have been described by 

 Packard ('Text-book of Entomology/ p. 585), Berlejse 

 (' Gli Insetti/ vol. 2, p. 218), and Williams and Euxtou 

 (Trans. Ent. Soc. London, 1916, p. 88j. In other cases 

 these organs appear to be part of the amnion rather than of 

 the embryo itself; instances of this are given by Riley 

 {vide Packard, Text-book, p. 585) and Kershaw (Bull. 

 Trinidad Dept. Agric. xii. 1913, p. 94). 



