externally from the male; this trifling difference, 

 however, lies partly in the more conspicuous gen- 

 erative orifices and to some extent in the appear- 

 ance of the fourth joint of the legs, which often is 

 swollen; but chiefly it lies in the diminutive so- 

 called ovigerous legs under the body which are usu- 

 ally not so well developed as those of the male. 

 This completes the picture of the outside — if 

 indeed an adequate representation in words ever 

 can be possible of such a monstrous mite. The in- 

 ternal structure is even more singular. Unlike all 

 other animals, wherein the body is distinguished 

 apart from the appendages as being the seat of 

 the vital organs, the sea-spider has all its principal 

 organs concentrated in the appendages. The ali- 

 mentary canal, although beginning at the pro- 

 boscis and ending at the opisthosoma (hind-body) , 

 is lodged largely in the limbs, sending long sac- 

 like processes into these appendages. Also, on each 

 side are the generative glands, sending their pro- 

 longations into the appendages where the opening 

 duct is to be found on the second segment of the 

 forward pairs. No gills or other organs of respira- 

 tion are present: the animal absorbs by means of 

 its integument the oxygen necessary for its blood. 



[34] 



