REPORT ON THE SIPHONOPHORvE. 295 



Androphores (PL I. fig. 3, h; PL II. fig. 7; PL VII. figs. 46, 49, h).— The male 

 gonophores are slender medusoid persons. Their form is more or less cylindrical, some- 

 times more spindle-shaped, at other times more club-shaped. The basal pedicle, or the 

 male gonocope, is much shorter than the female. The outer envelope, or the umbrella, is 

 very thin walled, often armed at the distal end with four small groups of nematocysts 

 (fig. 46, wo). The four radial canals (fig. 46, hr), which arise from the peduncular canal and 

 run divergently in the subumbrella, are very narrow and difficult to observe, especially in 

 adult persons ; they are connected at the distal end of the umbrella by a small ring-canal 

 (fig. 46, he). The spermarium is formed by the thick-walled cylindrical manubrium. 

 The sperm (fig. 46, hs) lies, as usual, between the thin exoderm of the manubrium and 

 its thick entoderm, the axial spadix (hx), but separated from the latter by the fulcrum; 

 it has been derived from the exoderm. 



Gynophores (f). — The female gonophores are much more varied in shape and 

 composition than the androphores. They are easily distinguished from these by their 

 more rounded (usually pear-shaped) form and their longer stalks. There occur the 

 following remarkable modifications : — A. Monovone gynophores. — Each female medusome 

 develops only a single large ovum, (l) The gynophore develops a single very large 

 ovum, surrounded by a double envelope ; the inner envelope is the thin manubrial wall 

 containing a smaller or larger blind spadicine cavity, sometimes a network of irregular 

 spadicine canals ; the outer envelope is the umbrella of the medusoid person, with four 

 narrow radial canals and a small distal ring-canal connecting the latter ; this is probably 

 the normal and most frequent form of the ripe gynophore. (2) The same form, but 

 with four blind radial canals (reduced in the distal half). (3) The same form (as 1 

 and 2), but with eight equidistant regular radial canals (fig. 12). (4) The same 

 form (as 1 to 3), but with a variable number (five to ten) of irregular, branched 

 and anastomosing, spadicine canals. (5) The same form (as 1 to 4), but without 

 radial canals in the reduced umbrella. B. Polyovone gynophores. — Each female medusome 

 develops an ovarium, composed of a variable number of ovules, placed in the wall of the 

 modified manubrium. The umbrella seems to be usually reduced, very thin walled, 

 without radial canals ; often it has disappeared. (1) The gynophore is a medusome with 

 rudimentary umbrella ; the spadicine canal (or the original gastral cavity of the Medusa) 

 is central, straight, and runs in the axis of the manubrium (PL II. figs. 9, 10); the 

 ovules are regularly disposed around it. (2) The gynophore is a medusome with rudi- 

 mentary umbrella ; the spadicine canal is excentric, curved, and runs on one side of the 

 manubrium ; it embraces the ovarium as a crescent-shaped or semicircular blind canal. 

 (3) The gynophore is a simple sporosac, the manubrium without umbrella ; the ovules 

 are arranged equally around the central spadicine canal. (4) The gynophore is a 

 compound sporosac. without umbrella, two or three (rarely more, sometimes only one) 

 buds developing from off the outside of the primary manubrium (PL II. fig. 11). 



