34 



DISCOVERY REPORTS 



ARTIFICIAL KEY TO THE DETERMINATION OF ANTARCTIC 

 AND SUB-ANTARCTIC SPECIES OF NYMPHON 



1 . Auxiliary claws absent or vestigial 2 



Auxiliary' claws well developed 12 



2. Four terminal palpal segments long, subequal 3 



Four terminal palpal segments of different size; two terminal segments together from 



§-i| of second segment 4 



3. 40-51 denticulate spines in adults ; 90-1 10 spinules on movable finger of chela ; legs smooth ; 



3 ovigeras in Fig. 10 b A^. clmiroti, Bouvier 



30-31 denticulate spines in adults; 70-85 spinules on fingers of chela; legs setose, setae 



very fine A^ charcoti var. ( ? = lanare, Hodgson) 



4. Oviger base arises from middle of neck 5 



Oviger base in contact with first lateral process 7 



5. Eyes well developed [second tibia the longer segment; 90-100 spinules on movable finger 



of chela which has the tip recurved] N. longicoxa, Hoek 



Eyes absent ; ocular tubercle obsolete 6 



6. Spur on distal end of femur ; first tibia rather longer than second ; 50-65 spinules on each 



finger of chela ; tarsus and propodus subequal N. hamatum , Hoek 



No spur on distal end of femur ; second tibia the longer segment ; 38 and 55 spinules on each 



finger of chela; tarsus just over one-half of propodus N. procerum, Hoek 



7. Neck long, lateral processes separated by their own diameter or more 8 



Neck short, lateral processes separated by half their own diameter, or less, as a rule 10 



8. Spinules on each finger of chela less than 20 (10-13) 9 



Spinules on each finger of chela more than 20 (28-42) [palm long and narrow ; S oviger of 



type I second tibia the longest segment ; 3-4 long setae at distal end of femur] 



A'^. tsnuipes, Bouvier 



9. Eyes well developed palm very short ; (^ oviger of type I ; first tibia the longer segment ; 



second coxa half as long again as the sum of the other two A^ proceroides, Bouvier 



Eyes absent, though ocular tubercle present; second tibia the longest segment; second coxa 



nearly three times the sum of the other two N. longicollum, Hoek 



10. First tibia the longer segment ; tarsus longer than propodus ; 38-48 spinules on each finger 



of chela ; 23-38 denticulate spines on oviger 11 



Second tibia the longer segment ; tarsus four-fifths of propodus ; 60-65 spinules on each 



finger of chela; 48-50 denticulate spines on oviger A^. capense, Hodgson 



11. Eyes and ocular tubercle absent; tarsus twice as long as propodus A', compacttim, Hoek 



Eyes present, ocular tubercle high ; tarsus half as long again as propodus or rather less 



N. australe, Hodgson 



12. Spines on four terminal segments of oviger not denticulate and numbering less than 



10 (5-9) [(? oviger of type I a; 6-9 spinules on each finger of chela; tarsus one-fourth 

 of propodus, the latter spinose on ventral margin; neck short] ...A'^. adareamim, Hodgson 

 Spines on four terminal segments of oviger denticulate 13 



13. Four terminal segments of palp each long, third and fourth subequal and longer than 



second and fifth which are again subequal [cj oviger of type I b ; 40-60 spinules on 



each finger of chela, fingers slender and bent distally] N. brachyrhynchum , Hoek 



Four terminal segments of palp of different size ; two terminal segments together vary from 



equality with, to one-fourth of, second segment 14 



