Re exopod 



Ri endopod 



Re 1, etc. exopod segments 



Ril. etc. endopod segments 



The prosome of most spinocalanids is fragile; many 

 specimens are broken between Thl and Th3. There is 

 also a tendency for the Ce ventrolateral margin to curl 

 outward (see Spinocalanus usitatus). The sutures 

 between Ce and Thl and Th4 and Th5, are clear on 

 most females. Sometimes, as with S. magnus, the 

 specimen must be cleared in glycerine to trace the un- 

 tiroken suture; this suture is more easily seen in un- 

 stained material. 



The caudal setae are extremely fragile, and in some 

 species have probably never been seen intact. Usually 

 the caudal setae are represented by short broken 

 bases, and even the bases may be missing. 



All appendages are fragile. Probably most damage 

 is caused by the net in sampling; if the loss of append- 

 ages were due to the fixative, great numbers of 

 detached appendages would be found in the samples, 

 and such is not the case. Some damages probably oc- 

 cur naturally, and the frequent abnormalities of the 



swimming legs are probably due to these damages (see 

 below). 



Al of females is most often broken, usually at a 

 suture distal to segment 12. This appendage is intact, 

 however, on most males, where the segments beyond 

 10 are more or less fused. Certain extraordinarily large 

 setae on Al are nearly always broken at the base. 

 Esthetes are fragile and usually only indicated by 

 their short bases. 



In the Al armature (Table 4) there are probably no 

 specific differences between females of Spinocalanus 

 and Mimocalanus (except perhaps in 5. antarcticus 

 and S. magnus: segment 15 with only 1 seta). In 

 males, only segment 14 separates Mimocalanus and 

 Spinocalanus species; 18 other segments have 

 equivalent armature; 6 other segments show specific 

 differences, and therefore do not consistently separate 

 the 2 genera (segment 8 could never separate the 

 genera). 



Al armature could not be completely verified for all 

 species, since some specimens had only partial or no 

 Al. Apparent deviations from Table 4 are noted and 

 should be reexamined at each opportunity. These ap- 

 parent deviations, except in the two species noted 



Table 3. — Continued. 



