27 



supra-cesopliageal ganglion, have a special function, which 

 may be olfactory. 



The Repkoductive Organs. 



The reproductive organs are paired, and as already 

 stated, the sexes are separate. 



In the female (Plate II., fig. 4) the ovaries are large 

 kidney-shaped organs lying on each side of the anterior 

 portion of the stomach and extending from under the first 

 pair of feet to the base of the second maxillse, when 

 fully matured. Each oviduct {od .) arises near the anterior 

 end of the ventral surface of the ovary, and courses . 

 j)osteriorly as a narrow tube till it enters the genital 

 segment. It then expands rapidly, and passes to near the 

 end of the segment. It then reverses its course, passing 

 forward to the central portion of the segment, where it 

 turns again in a ^losterior direction, and passing out to the 

 centre of each half of the segment, it opens to the exterior 

 just under the fifth feet. Each oviduct thus forms two 

 loops in the genital segment. On the ventral aspect of 

 the loops of each oviduct there is a short, semi-transparent 

 cjdindrical tube [sg.) with the anterior end closed and 

 rounded, and the posterior produced into a fine duct, 

 which communicates with the oviduct near its extremity. 

 This organ is evidently a cement gland for secreting the 

 enclosing membrane of the ovisac. Each vulva (fig. 6, vu.) 

 is situated near the middle line behind the junction of the 

 genital segment with the abdomen. It appears to consist 

 of a simple opening leading into the vagina which expands 

 into a " receptaculum seminis." This is an elongated sac 

 passing from the median line to the oviduct, which it 

 enters alongside the duct of the cement gland. 



In the male the reproductive organs (Plate II., fig. 5) 

 consist of a pyriform testis, on each side, situated in a 

 position corresponding with that of the ovary. It is only 



