REPORT ON THE DEEP-SEA MEDUSAE. 83 



("spermaria," sm) form eight horseshoe-shaped or U-shaped glands, which lie adradially in 

 the sulmmbral wall of the coronal sinus. The convex arch of each horseshoe is turned 

 distally, and nearly touches the proximal margin of the coronal muscle (mc), whilst the two 

 parallel limbs of the horseshoe are directed proximally (or centripetally), and their points 

 nearly touch the pyloric stricture (gy). The eight U-shaped reproductive glands therefore 

 extend in an adradial direction through nearly the entire height of the coronal sinus (os), 

 and only leave a small part of the upper (proximal) margin and the lower (distal) margin 

 of its subumbral wall free. The eight genitalia are connected in pairs, in such a way that 

 a pair lies between each two perradial gastral openings {(jo). The two genitalia of each 

 pah- are divided by the intergenital longitudinal muscle (ms) in the upper (proximal) 

 half, by the septal nodes (hi) in the middle, and by the interradial deltoid muscle (md) in 

 the lower (distal) half. The four pairs, on the other hand, arc divided by the four gastral 

 openings (go) in the upper half, and by the four perradial deltoid muscles (md) in the 

 lower half. The lower half only lies freely in the coronal cavity of the umbrella (he), 

 whilst the upper half is concealed deep in the funnel cavity (ie). The four limbs of each 

 pair run nearly parallel in the upper half (in the funnel cavity), whilst the two 

 genitalia of each pair diverge distally (in the coronal cavity of the umbrella), as they 

 diverge parallel to the two limbs of the interradial deltoid muscle. The two limbs of 

 each genitalium converge, however, at their distal end, and are connected there by the 

 cords of the horseshoe, whose convex outer margin nearly touches the inner margin of 

 the coronal muscle (comp. PL XX. fig. 8, and PL XXV. fig. 1). The two limbs of the 

 horseshoe-shaped genital band are broadest below (1 cm.), and gradually narrow as they 

 run up (0"5 cm.) towards the proximal points of the two limbs (PL XXIII. fig. 38). 

 The limbs are of ecpaal length in Periphytta mirabilis, whilst in Periphylla hyacinthina 

 the lateral limb (next the gastral opening) is much shorter than the medial limb 

 (next the septal nodes). (Comp. my System, PL XXII. figs. 13, 16.) 



Structure of the spermaria (PL XXIII. figs. 38-48). Each of the eight horseshoe-shaped 

 genitalia shows a projecting, nearly adradial, selvage, the genital rib ("costa genitalis, 

 sterigma," st) between its two limbs. It consists of a firm selvage-like thickening of 

 the fulcra! plate of the subumbrella and of the weak axogenital longitudinal muscle 

 (mx) lying on it. Gelatinous transverse selvages run, as in a pinnated leaf, from both 

 sides of this midrib, and serve to support the separate pouch-shaped transverse folds of 

 the genitalium (fig. 38). More minute examination shows that the testis represents a 

 broad U-shaped arched band having many transverse folds along its whole length. The 

 convex lateral margin of the U-shaped band is fastened to the subumbral wall of the 

 ring sinus, whilst the concave, medial margin projects slightly into the canal space of 

 the ring sinus. The separate pouch-shaped, arched-out, transverse folds of the genital band, 

 amounting to about 50 to 60 in each genitalium, are of a narrow, oval or conical shape, 

 and bear the same relation to the midrib that the pinnae do in a pinnate leaf. Numerous 



