28 EXPLANATION OF ANATOMICAL PLATES. 



VI. GENERATIVE APPARATUS — PLATE E. 

 FL'. 8. Generative organs of AthaUa ccntifnlia : aa, ovarial tubes; cc, uterine cavities; d, separate 



oviducts ; e, ejaculatory oviduot; f, sperniatheca ; g, poison gland; /(, its vessel; 10,11, 



terminal ganglia. 

 Fig. V. Generative organs of Ranatra linearis : the letters correspond to the same parts as in fig. 8; 



g, supposed swimming bladder, with part of the intestine. 

 Fig. 5. Male organs of Athalia centifolia : aa, smaller testes ; bb, ducts ; c, larger testis ; dd, vasa 



deferentia ; e, vcsicula seminales; h, cjaeulatory duet ; i, exterior valves. 

 Fig. 9. Hydrns piceus : aa, testes ; bb, vasa deferentia ; cc, principal seminal vessels ; cecc, various 



accessory vessels ; /, ejaculatory duct ; g, copulative armature of the vagina. 

 Fig. 4. Testicles of Silpha obscura, greatly magnified. 



