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other, namely one anterior vertical, and one posterior horizontal, which 

 latter is longer in the most developed glands. The former is laterally, 

 the latter ventrally imbedded in the liver. The genital glands receive 

 their shape from their situation behind the stomach beneath the heart 

 and above the intestine, the heart being situated between the horizontal 

 portion of the gland and the carapace. The ovary consists of two distinct 

 halves or different glands which however in the median line lie so close 

 together that they appear as one. They are connected by connective 

 tissue, and between the lower half of the vertical portion seems to be 

 a communication between them. I have not however seen any egg in 

 that bridge so it may not be formed by sexual elements. The ventral 

 surface of the ovary is concave to make place for the intestine. It is 

 more difficult to get an exact idea about the shape of the testis with 

 the material on hand. The two lateral parts are however more closely 

 connected and the intestine seems to pierce through the organ. 



The greatest interest is connected with the fact that, altough these 

 animals seem to be completely dioic, with regard to the appearance of 

 their generative glands, every individual of both sexes is provided 

 with two pairs of genital ducts, namely, two anterior ones leading to 

 the »orifices« on the coxopodites of the third pair of legs, and two 

 posterior to those of the fifth pair. In the male specimens (see Fig. 1) 



Kg. 1- 



the posterior ducts have their origin on the upper lateral surface of 

 the gland about 3 mm from the posterior end and extend in a lateral 

 backward and downward direction in an almost straight line to the 

 opening on the fifth pair of legs. These ducts correspond to the vasa 

 deferentia of the common crayfish, but are very much shortened in 

 comparison with them and do not make any convolutions. Dr. von 

 Ihering has observed these and expressed the same opinion about 

 them. The ducts of the anterior pair take their origin close to each 

 other in the median line near the angle between the vertical and hori- 

 zontal portions of the testis. From this starting point they extend, as 



