136 



COPEPODA 



think the similarity with the other species of this genus, as pointed out by Giesbrecht as far as U. 

 major is concerned, is better marked, but it may just as well be a species not yet rediscovered. A. Scott 

 also regards the male of Brady's E. australis as identical with this species, and so does Sars; Brady's 

 figs 8 —9 PI. XXI show that it belongs to an Uudcjichcetc^ but is far too incomplete for the drawing of 

 further conclusions. 



38. Undeuchaete major Giesbr. 

 (PI. V figs 2 a— d; text-fig. 36). 



1883? 9. Euchseta australis n. sp. Brady, p. 65. pi. XXI figs 5 — 11. j 1905. Scolecithrix cristata Giesbr. Farran, p. 35. 



9. — — — Esterly, pp. 147 — I48fig. 16. 



Chirudina angulata n. sp. G. O. Sars, p. 13. 



Undeuchtete major Giesbr. Pearson, p. 15. 



— — G. O. Sars, p. 3. 



— — — Farran, p. 37. 



9. ^ — — — V. Breenien, p. 43. fig. 49. 



18S8. Undeuchaete major n. sp. Giesbrecht, p. 335. I903' 



1892. — — Giesbr. Giesbrecht, p. 227, pi. 37. 1905. 



1895. — — — — p. 251. j 1906, 



189S. — — — Giesbrecht & Schmeil, p. 34. ' 1907 



1900. — — — J. C. Thompson, p. 278. 1908. 



1903 <S- Scolecithrix cristata Giesbr. J. C. Thompson, p. 21, pi. 1908, 



III figs 1—5. 1909. 



1904. — — — Wolfenden, p.m. 191 1 

 1904. — — — Cleve, p. 1 98. 



A. Scott, pp. 61—62. 

 Wolfenden, p. 243. 



Description. i% Size of female from Thor St. 90: 4-92 mm.; anterior division 3'9i ; urosome 

 1-04 mm. Giesbrecht's specimens measured 4-5 mm. and Scott's 4-8— 64 mm. 



The lateral corners of the thorax are asymmetrical in a similar way as in Und. minor \ on the 

 left side it is triangularly pointed, more so than shown in Giesbrecht's fig. 5a (Taf. 37); on the right 

 side it is more rounded, and bears a small conical process just in front of the end. The oblique hinder 

 margin has two groups of short spines. 



The antennulae are like Giesbrecht's description, but the measurements are somewhat dif- 

 ferent; the segment 17, f. inst, is scarcely, not distinctly, twice as long as the segment 12. The mouth- 

 appendages are scarcely different from Giesbrecht's description. The natatory legs differ in a few 

 minor points from those of U. tnmor\ the Se Re II in the first pair of legs extends somewhat beyond 

 the middle of Re III, but does not reach the end of it; the accessory tooth of Se Ri I of pes II, which 

 was just indicated in the preceding species, is fairly distinct. The inner margin of the second basi- 

 podite of the fourth pair of legs is not quite smooth, but finely undulated, and the posterior surface 

 possesses near margin just above the insertion of Si from one to four closely placed short spines. 



The labruin is in lateral view like that of the preceding species. The oral surface of the 

 labrum (fig. 2 a) shows a structure similar to that of Cliiridina Street si (fig. 4 b), though less complicated; 

 the Jirst group consists of about 25 short hairs, placed in an oblique row; the second to the Jifth 

 groups possess a regular median row and a more or less irregular lateral portion. The transverse rows 

 of setae are very regular. The chitinous framework is well developed. The lamina labialis, as seen 

 in fig. 2 b, is distinctly divided into three divisions, and is distinctly striated; in front of the lamina a 

 median slightly curved series of about 20 setae is found, and a lateral one of numerous setae, of which 

 the posterior ones are rather delicate. Behind the lamina 4 spinous areas are found on each side, of 

 which the first one is almost obsolete. The arrangement of the setae upon and behind the labial lobes 

 differs from that of following species by the comparatively few and long setae in the second series. 



