and vn Six New Species of' Cruatacccy &^c. 185 



of the body, I have been unable to trace the anatomy of the 

 blood-vessels farther. On placing a live caprella under the 

 microscope, the blood is seen circulating through the vessels 

 of the antennae in a most beautiful manner, passing from the 

 body by means of the superior or arterial trunk, and return- 

 ing again by means of the inferior or venous. The blood 

 globules in these vessels are seen passing onwards steadily 

 and continuously ; some of them are often lost to the field of 

 the microscope, passing off probably by means of the smaller 

 lateral branches. Sometimes it is oscillatory, that is to say, 

 the globules are seen vibrating backwards and forwards, but 

 this is only occasional, in general it is continuously onwards, 

 frequently, however, they jerk suddenly forwards, but they 

 subside as rapidly into their usual course. The circulation 

 does not seem to be guided by any apparent pulsation ; the 

 globules are spherical, not very numerous, and are suspended 

 in a colourless liquid. I have not been able as yet to detect 

 any appearance of a nervous system. 



The organs of reproduction are extremely curious, and are 

 <;omplicated in the female. I am not acquainted with their 

 peculiar organization in the male. 



The ovaries (fig. 2. PI. III.) are two long slender bodies which 

 lie along each side of the intestinal canal. Each of them arises 

 from the posterior part of the post-occipital segment ; during its 

 course through the first thoracic segment it is thin and slender, 

 but as it reaches the second it becomes considerably larger ; 

 and about the middle of this segment each of them gives off a 

 small duct — the oviduct ; these meet one another in the mesial 

 line by means of one common opening through the roof of the 

 ovarian pouch ; another duct is given off in the same way at 

 the second ovarian opening, and the ovaries then end at the 

 posterior extremity of the fourth thoracic segment. The in- 

 ternal structure of the ovaries is like those of the caligi ; they 

 consist of a single row of cells, each of which contains an e^^. 

 The external organs of generation in the female ai'e composed 

 of a series of plates four in number, which, when enlarged, 

 forms a floor to a coiTesponding cavity in the abdominal sur- 

 face of the two middle thoracic segments ; this forms the ovi- 

 ferous sac or pouch. When the animal is with spawn, these 



