vd 



FIG. 3. Paired genital openings of 

 different classes of arthropods. A, the 

 most primitive, of LimiiluH polyphernus : 

 gen. p, generative papill* ; d, duct ; vd, 

 vas deferens ; t, tendinous stigmata ; stiff, 

 stigmata ; e, external branchial muscle ; 

 ant, anterior lamellar muscle. After Ben- 

 ham, with a few changes. , lobster 

 (Ifomaru* vulgari*), $ : of, genital 

 aperture on 3d pair of legs ; ov, ovary ; 

 11, unpaired portion of the same ; od, 

 oviduct. C, ? , scorpion : ov, ovary, with 

 a single external opening. D, J 1 : t, te*tis; 

 ni . vasa deferentia ; #b, seminal vesicle ; 

 (t, glandular appendage ; p, penis. 

 After Blanchard. E, a myriopod (Glo- 

 meris nmrginatn, 9): OK, ovarian sac, 

 laid open ; <xi, paired oviducts, f, cf : 

 t. tcslis ; ffrd, common vas deferens ; pa, 

 paired ducts. After Favre, from Lang. 

 (j, Lepiama saccharina, young tf : va, 

 vas deferens, ed, ejaculatory duct; ga, 



external appendages. After Nassonow. 

 ff, Ephemera, 

 lets. After P 



. 

 ff, Ephemera, cTj showing the double out- 



almeii. 



