COPEPODA 



149 



inside (cf. Ch. abyssalis). The maxillulae have in addition to the 4 Sp. on the posterior surface of Li 1 

 a short S 15; the Le 2 has 5 setae, the Li 3 has 4 setae and the Basp. Ill has 5 setae; the endopodite 

 has 3 setae in Ri I, 5 setae in Ri II and 7 setae in Ri III. The exopodite has 10 setae of about equal 

 length, and the Le has 2 short proximal setae and 7 long distal ones. The maxillae are scarcely dif- 

 ferent from those of Ch. abyssalis cf. PI. V fig. 5 c, and the maxillipeds have the third basipodite 33 as 

 long as the endopodite and 

 i-6 as long as the two basal 

 segments. 



The first pair of legs 

 is very much like that of Ch. 

 abyssalis; the articular mem- 

 brane between Re I — II is com- 

 pletely wanting posteriorly 

 and only slightly developed 

 anteriorly; the Se of Re I 

 distinctly extends beyond the 

 end of preceding segment, 

 and so does Se of Re II. 

 The articulation between Ri 

 I — II in the second pair of 

 legs is wanting posteriorly, 

 but is marked by an indi- 

 stinct line anteriorly, and the 

 Se of Ri I is slightly marked 

 as seen in text-fig; the arti- 

 culation between Re I and II 

 is almost wanting posteriorly; 

 the St. has 50—60 short teeth. 

 The Se of Ri I is well devel- 

 oped but without an acces- 

 sory tooth in the fourth pair 

 of legs, and the inner margin 

 of the second basipodite is completely smooth. The only difference between the male and female is 

 found in the fifth pair of legs in the male (text-fig. 41 k); this is distinctly different from the preceding 

 species by the segmentation of the left exopodite and by the wanting terminal setae. The labrum etc. 

 is scarcely different from that of Ch. Streetsii (cf. text-fig. 38 a); along the transverse ridge which limits 

 the labrum in front about 10 rather delicate setae are found. The oral surface of the labrum (PI. VI 

 fig. 1 a) is rather characteristic, though showing most similarity to that of Ch. Streetsii; the supporting 

 chitinous framework is less developed. The first group of the longitudinal series consists of numerous 

 short spinules; the second group consists of a single longitudinal row of fairly long setae; the third 



Text-fig. 41. Chirudina notacantha G. O. Sars. 



a. fcC. Head X 30. b. abdomen etc. X 30. c — d. Pes V dext Ri -p Re IcnjII from 



the right and partly from behind X c. 50. e. Pes V Ri sin. X 66. f. Pes V sin. Re 



II— III X 75- g- yd" (St. V) rostrum, h— i. (St. Vj fifth thoracic tergite from the left 



and from above, j. (St. VJ furca X 29. k. (St. VJ Pes V in ant. view X 29. 



