studies on marine Ostracod.s 



215 



than in the female. The number of filaments on the sensory bristle of the fifth joint and 

 on the distal bristles seems to vary somewhat, as appears from the following table: (The lengths 

 are the averages of right and left first antennae; in most cases, however, the right and left 

 bristles were almost exactly of the same length; the difference was never preat.) 



On a defective specimen from S/S ,,M i c h a e 1 Sars" the sensory bristle of the 

 fifth joint had twenty filaments on both antennae, one f-bristle had 46 and one g-bristle 47 fila- 

 ments. The filaments on the sensory bristle of the fifth joint are comparatively longer than 

 those of the female, most of them are somewhat spool-shaped, though only slightly so. B-bristle 

 (fig. 6): The three proximal filaments are metamorphosed for seizing the female; distally of the 

 sucker these three filaments have one or a few chitinous verruciform swellings; the two distal 

 filaments are of the same type as in the female. C-bristle: The proximal filament is metamor- 

 phosed for seizing the female, it is of the same type as the three proximal filaments on the b-bristle; 

 on the right antenna of the specimen from M/S ,,A r m a u e r Hansen" the second filament, 

 counting from the base, also had a suctorial organ; this suctorial organ, fixed to the base of the 

 filament, was of a somewhat pathological type; as in other respects the filament was of about 

 the same type as the more distally situated filaments, this case is probably to be considered an 

 abnormality. The c-, f- and g-bristles are, as shown in the above table, subequal and of about 

 the same length as the shell. In other respect this limb agrees with that of the female. 



Second antenna: — The p r o t o p o d i t e is slightly more powerful than 

 in the female; in one specimen with a shell 12.5 mm. long it attained a length of 4,0 mm.; while 

 in a female with a shell 14,5 mm. long it only measured 3,5 mm. The endopodite is 

 almost exactly of the same type as in G. Agassizi, as this is shown in pi. I, fig. 19, G. W. MCLLEli, 

 1895. The bristles of the first joint, all situated proximally on the joint, are quite like the 

 female's. The second joint has four short, subequal, bare bristles (cf. the accompanying figure 8); 

 no less than two of the four males investigated were obviously pathological in this character. 

 The ventral bristle of the end joint is fixed about half-way along the joint and attains about 

 the same length as the second joint or is sometimes even somewhat longer. 



Penis: — This has the fundamental type usual for this sub-family. For details the 

 reader is referred to the accompanying drawing no. 25; not quite all the bristles are shown in this. 



The other organs agree very well with those of the female; in one case I found on the 

 first exopodite joint of the fifth limb only five, not six, bristles in the row next to the main tooth. 



