212 



COPEPODA 



The labrum is, as seen in Wolfenden's fig. 41, more elongated than that of S. uiaguus (PI. VII 

 fig. 8 a), and strongly produced in front; the hinder portion of the labrum is, as in most other species, 

 marked by an anteriorly convex line. I am fairly convinced that the anterior as well as the posterior 

 portion of the labrum belongs to the mandibular and not to the antennal somite; the anterior portion, 

 accordingly, does not correspond to the epistoma of Euchcetc. The arrangement of bristles on the 

 anterior surface is very characteristic (PI. VII fig. 7 b). In the middle, most anteriorly, is a forward convex 

 row of about 30 long bristles. A little more posteriorly we have on each side a long row extending 

 laterally from the middle in front towards near the hinder margin; the setae of this row are decreasing 

 in length posteriorly; the right and the left parts establish an acute angle open posteriorly, and, 



thus include a more posterior row, forming a more obtuse 

 angle, of shorter setae. 



In addition to the marginal setae, posteriorly irregular 

 groups of short setae are found on each side. The oral 

 surface of the labrum is rather characteristic, the first 

 group is poorly developed, consisting of small granules 

 and is well separated from the groups 2 — 4, which are more 

 or less fused and consist of fairly strong, densely placed 

 setae; behind, a group of small granules is observed (fig. 

 7 c, which is turned upside down). A lamina labialis (fig. 

 7 d PL VII), consisting of a median and two lateral parts, 

 is found. In front of the serrula 6-dentata are two rather 

 irregular rows of delicate setae, as seen in figure. Between 

 the serrulae at least two groups of short spines and a 

 longitudinal row are seen on each side. The lobus labialis 

 possesses a wide inner row of numerous hairs, and an 



Text-fig. 66. Lophothrix frontalis Giesbr. outer one f f ew hairs; both rows start posteriorly from 



a. fO. Genital somite X 33- b. Y9 (St. V) Pes V 



X 59 . c. Yd (St. V). Abdomen x 33. d. Yd" (St. V). a median group consisting of an inner portion with 

 Pes v x 59- e. Y <5 (St. IV). Abdomen x 33- f- Yd numer ous denselv placed hairs, and an outer portion with 



(St. IV). Pes V X 59- 



scattered hairs. More posteriorly and laterally, two groups 

 of a few hairs as well as irregularly placed hairs are found. The intestinal tract is curiously twisted. 

 In front of the oesophagus a short coecal sac is observed ; behind, the stomach is gradually attenuated, 

 and forms a slight ventral convexity. At the insertion of the third pair of legs the intestine is 

 suddenly, in a sharp bend, turned upwards and directed forwards, being thus placed dorsally to the 

 mentioned part; somewhat in front of the maxillipeds it is continued through a second curvature 

 into the intestine proper. 



fc?. Size of male from Thor St. 183 was 5-66 mm.; anterior division 4-19 mm.; urosome 1-47 mm. 

 Scott's specimens measured 575 mm. 



The body is slender and attenuated in front as well as behind; in dorsal view, scarcely in 

 lateral, a trace of rostrum, is observed. The rostrum is on each side continued into two fairly long 



