studies on marine Oslracods 581 



at present. C. Claus's view seems to be supported by the fact that the part on which the f- 

 and g-bristles are attached almost always composes the distal part of the second joint; thus 

 in the male the clasping organ issues on the side of and not distally on this joint and in the female 

 these two bristles issue in most cases distally of the h-, i- and j -bristles. In addition in the male 

 this part on which the f- and g-bristles are attached is often somewhat contracted proximally, 

 so that it gets a somewhat joint-like appearance (cf. fig. 13 of Conchoecia symmetrica below). 

 G. W. MtJLI.ER's view seems to me to be supported by the following facts. The part on which 

 the f- and g-bristles are attached is never, either in males or females, marked off proximally 

 and is never moved by special muscles; on the contrary it is quite immoveably joined to the 

 second joint. This is, of course, not a conclusive proof. Complete union between originally 

 well divided joints is, of course, far from being rare in the Ostracod group. (But it seemed to 

 be conclusive for G. W. MULler, as this investigator writes, 1894, p. 38: ,,Einschniirungen sind 

 noch keine Grenzen. So deutlich die Ansicht von Ci^AUS aus den Figuren ersichtlich sein mag, 

 so kann ich doch auf eine Discussion dieser Figuren erst eingehen, wenn die Grenzen der Glieder 

 scharf gezeichnet sind".) Besides, the appendage explained by G. W. MtlLLER as an end joint 

 is well marked off proximally in the males and is moved by a special muscle. This is not conclu- 

 sive evidence, either; accessory appendages that are well defined proximally and furnished with 

 special muscles are found, of course, pretty often, e. g. the epipodial appendage, etc. (In [all?] 

 males of the genus Euconchoecia the part explained by G. W. MOli-EU as the end joint has the 

 form of a simple cylindrical joint with bristles distally on the left second antenna. Is this prim- 

 itive or secondary? The latter alternative seems to me the more probable.) The fact which 

 seems to me to afford perhaps the most decisive proof in favour of G. W. MOLler's view 

 is that in the females of the genus Halocypris (the genus put forward by C. Claus in support 

 of his view!) and in a number of females in the genus Conchoecia the part on which the h-, i- 

 and j -bristles are attached is always distinctly defined proximally and that it is moved by a 

 special muscle; see fig. 12 of Halocypris brevirostris below (even in forms of the genus ConcJioecia 

 in which this part is quite joined to the second joint this muscle is more or less developed). 



Genus Halocypris J. D. Dana. 



For synonymy see G. W. MCLLER, 1912, p. 57. 



Description: — Shell: — Always very short, its height being at least two-thirds of 

 its length. The rostrum is short, sometimes it is even scarcely developed at all. Of the two 

 unsymmetrical glands the left one opens out just in front of the postero-dorsal corner of the shell, 

 the right one at about the boundary between the ventral and posterior margins of the shell; 

 sometimes, however, the latter gland is somewhat displaced dorsally. Apart from these there 

 are no great accumulations of glands at all. The pores of the surface are moderately large and 

 easy to observe. The part of the selvage that runs witliiii the rostrum has no spine. 



