158 



COPEPODA 



As a good deal of confusion exists as regards the determination of several species, I think the 

 following synoptic key of the adult females may be useful. 



j_ One of the apical setae of the maxillae with numerous short spinules and 



a few long ones. Lateral corner rounded. 

 2. The genital somite on the left side with a conical process. 4 mm. E. acuta. 



2. The genital somite on the left side dorsally a hairy process. On the right 



side of the vulva a laminous process. 3-5 mm. E. licbcs. 



I. All the apical setae of the maxillae of the usual structure. 



2. Si of the furca distinctly shorter and thinner than St. 2. Lateral corner rounded. 



The posterior process of the vulva longer than the anterior. 10 mm. E. glacialis. 



x. Si of the furca distinctly longer than St 2. 



4. Lateral corner pointed. 



5. Lateral corner triangularly pointed without tuft of hairs 6-6 nun. E. tonsa. 

 e. Lateral corner with a well defined pointed process; distinct tuft of hair.s. On 



each side of vulva a median process. 8'8 mm. E. norvegica. 



4. Lateral corner rounded. 



6. 3 distinct processes on each side of the rather low genital protuberance. 



56 mm. E. bisinuata. 

 6. Without 3 distinct processes on the same level. 



7. Genital protuberance very deep, almost squarely truncate with a small median 



process on each side of the vulva. 67 mm. E. gracilis. 



7. Genital protuberance not very deep. On each side of the vulva in front of 



the posterior edge a laminous process. 

 8. Dorsally and behind on the protuberance small process. Le maxillulae with 



9 setae. Se Re I pes I long and slender. 8-9 mm. E. Hansenu. 



8. No such process observed. 



9. On the left side of the genital somite a conical process found 



10. The Se 2 Re III pes II does not extend to end of segment 11 mm. E. Farraiti. 



10. The Se 2 Re III pes II extends beyond end of segment 8 mm. E. barbata. 

 9. On the left side of the genital somite no conical process found. Se Re I 



pes I small or wanting. 



11. The genital protuberance is prominent with short anterior frange. 8'2 mm. E. Brady. 

 II. The genital protuberance not very prominent 



12. Shape of body clumsy. 6 mm. /:. Scotti. 



12. Shape of body rather slender. 9-5 mm. E. Sarsi, 



46. Euchaete norvegica Boeck. 



(PI. VI figs 3 a— f; text-figs 45 a— s.) 



1S64? Euchaete pestandreae Philippi. Boeck, p. 12. 



1872. — norvegica n. sp. Boeck, p. 40. 



1873. — carinata n. sp. Mobius, p. 271, tab. VII. 



1885 pars. Euchaete norvegica Boeck. G. O. Sars, p. 234, t. 19. 

 1892. — — — Giesbrecht, p. 246, taf. 



15, 16 and 37. 



