142 



COPEPODA 



oped setigerous process inwards, and the second segment has a similar one at the base in addition to 

 ones sitting in the middle as well as terminally (text-fig. 38 f). The mandibidae and maxillulae do not 

 show any features which were not mentioned in Giesbrecht's description. The maxillae are very 

 much like fig. 5 c of Ch. abyssalis. The third basipodite of the maxillipeds, which is almost twice as 

 long as the Basp. 1^2 and distinctly three times as long as the Ri, has along the exterior margin almost 



from base to tip on the 

 posterior surface a low 

 transparent lamella with 

 a distinct concavity in the 

 middle; the fourth lobe 

 of the second basipodite 

 is placed posteriorly, and 

 has a fairly long sensory 

 lobe surrounded by slen- 

 der hairs, in addition to 

 three setae (text-fig. 38 g); 

 anteriorly, and somewhat 

 removed from the tip, a 

 rounded protuberance is 

 found in the second basi- 

 podite, probably corre- 

 sponding to that of E. cur- 

 ticanda. The first pair of 

 legs has the inner margin 

 of the last basipodite 

 slightly convex, as seen in 

 text-fig. 38 h ; the Se of Ri I 

 has no accessory tooth in 

 the second pair of legs, and 

 no trace of it in the third 

 and fourth pairs (text-fig. 

 38 i) ; the inner margin of 

 the second basipodite in 

 the fourth pair of legs is in most specimens completely smooth, but in some has one or two short 

 stiff hairs corresponding to Giesbrecht's "sparlichen kurzen Spitzen". The glandular pores are like 

 those of Undeuchcete. The elevation in front of the labrum is smooth and fairly well raised; along 

 the posterior margin the labrum proper has as usual a median row of long and slender hairs divided 

 into a right and a left part, and a lateral shorter one, of more spine-shaped setae. The oral surface of 

 the labrum (fig. 4 b) is like that of Undeuchcete. The first group of the longitudinal series is placed 

 obliquely, and consists of about ten fairly strong setae ; the second group consists of two rather inde- 



] k 



Text-fig. 38. Chirudina Streetsii Giesbr. fQ. 



a. f 9. Head X 30. b. f 9. Abdomen X 18. c. f 9- Lateral corner from the right side X 18. 



d-e. f9. Left lateral corner X 18. f. f9- Antenna sin. Re X 57- g- f9- Maxillipes dext. 



in post, view X 57- b. f9. Pes I sin. X 57- i- f 9- Pes IV sin. X c. 20. j. y9 (St. V). Left 



lateral corner X 18. k. yd" (St V). Pes V in anterior view. 



