ON THE OVIPAROUS SPECIES OF ONYCHOPHORA. 373 



air, it is difficult to say wli ether or not they are amoeboid, as 

 is the case with the similar corpuscles found in the liquid 

 discharged from the uephridia (in O. oviparus). 



Reproductive Organs of the Male. — The male organs 

 of reproduction are, owing to the small size of the animal and 

 the brittle nature of the organs themselves, extremely difficult 

 to dissect in spirit-preserved material. I have, however, made 

 some observations on the subject in the case of O. viridi- 

 maculatns, and the following notes are perhaps worth 

 recording. 



The unpaired portion of the male duct (vas deferens) is 

 extremely long, considerably exceeding the entire length of 

 the animnl when at rest. It has very much the same 

 structure as described by Gaffron (1) in the case of 

 P. Ed ward si i. Its middle portion contains along spermato- 

 phore, while the terminal portion forms a long muscular 

 ductus ejaculatorius. The sperraatophore is in general 

 similar to that of P. Edwardsii. It appears to contain no 

 ripe spermatozoa, but numerous spherical sperm mother-cells. 

 It is irregularly swollen out at intervals, but the sperm 

 mother-cells occur throughout almost the entire length. The 

 outer cover of the spermatophore is a thick, homogeneous, 

 transparent, apparently chitinous sheath, and there appear to 

 be no spherical globules, such as occur on the surface of the 

 spermatophore in P. Edwardsii. 



Reproductive Organs of the Female. — Of greater 

 interest are the internal reproductive organs of the female, 

 which I have been able to study in freshly-killed specimens, 

 and of which I have already (15) given a short account in 

 the case of 0. oviparus. The ovary (0. oviparus and 

 0. viridimaculatus) is as usual placed far back in the 

 body cavity above the alimentary canal (figs. 4, 6, 12, 27, 31). 

 It consists of right and left halves united with one another in 

 front and behind (fig. 12), and attached by a mesoarium to 

 the pericardial septum in the mid-dorsal line. It contains a 

 large number of eggs, varying enormously in size according 

 to the amount of yolk which they have received, the structure 



VOL. 45, PART 3. NEW SERIES. C C 



