140 THE VOYAGE OF H.M.S. CHALLENGER. 



Crambessa (loc. cit.). They form four narrow bands, folded thickly like a frill, and shaped 

 like a horse-shoe, whose convex proximal arch projects centripetally in the interradius 

 (fig. 4, a). The four reproductive bands lie in the delicate gastrogenital membrane, on 

 the inner surface of the central bottom of the stomach, and are separated by a narrow 

 interspace from the outer edge of the stomach (gn) on the one side, and from the four 

 limbs of the gelatinous gastral cross (gh) on the other. When viewed from above 

 (fig. 3), or from below (fig. 4), it almost looks as if the distal ends of the inverted limbs 

 of each two adjacent arches of the horse-shoe, passed into one another at the distal end 

 of the limbs of the gastral cross, and so formed a connected genital ring. Closer 

 investigation, however, shows that the four interradial genitalia remain completely 

 separated, although the ends of their limbs nearly touch on the axial surface of the 

 perradial oral pillar. The last ends of the genital limbs are here bent down, diverging 

 again laterally ; they already lie in the four corners of the arm disk (fig. 6, sx). The 

 specimen of Leonura examined was a male. The testes are laid in cross folds like a 

 frill, in such a way that the whole genital band seems to consist of a large number of 

 small fusiform sacs. These sacs (the tranverse folds of the horseshoe-shaped band of 

 testes) lie thickly compacted, with their longitudinal axis perpendicular to that of the 

 band ; the sacs were shghtly filled with ripe spermatozoa. The conditions of the finer 

 structure in the genitalia, as in most other organs, resembled those of Crambessa. 



