COPEPODA 



209 



about to the end of the third abdominal somite. The antennulae appear rather clumsy, and their 

 measurements are scarcely different from Farran's figures. A proximal seta, in addition to the distal 

 one, was found in segments 12, 14 and 18; in contrast to Farran's fig. 14 no seta whatever was ob- 

 served in segment 10; the posterior seta of segment 24 is short, and scarcely extends beyond the end 

 of segment 25. The antennae are like those of S. minor, but the inner lobe of the endopodite has only 

 7 setae. The mandibular have on the inner side of the long and slender third basipodite two long 

 setae placed close to each other, of which the basal is the longer and stronger; the last segment of 

 the exopodite has 9 long setae. The maxilhtlae have 7 -j- 2 setae in the outer lobe. L,i I has 2, Li II 

 3 setae, Basp. Ill has 4 setae and Ri I — III 3 — j— 3 setae. The exopodite has 5 setae. The maxillae are 

 like Farran's figure, and possess numerous vermiform, but no amalliform, setae (PI. VII fig. 14a); the 

 maxillipeds are like Farran's figure, but the second lobe of the second basipodite bears a fairly long, 

 terminally hooked, and soft sensory seta. 



The first foot has a well developed Se in the first outer segment, almost reaching the middle of the 

 following segment. The second foot has the second basipodite rather broad ; medially proximally to the 

 insertion of Si a small tooth is observed, and laterally the margin is proximally produced into a strong 

 tooth; the Se of the first outer segment is long and slender, and the St of Re III has about 55 basally 

 fused teeth. The spinulation of the posterior surface is better developed than indicated by Far ran. 

 A glandular pore was observed at the base of Se 3 Re III. The third pair of legs has a well devel- 

 oped outer tooth in the second basipodite, and a short inner one, resembling that in the second foot 

 of S. obtusifrons. The fourth pair of legs has no inner marginal bristles in the second basipodite, and 

 no outer tooth. The St has a rather curious structure, as the marginal serrations are not completely 

 coalesced basally, leaving an elongated fenestra. Spinulatiou, consisting of about 15 rather small teeth, 

 is found on the posterior surface of the second inner segment. 



The fiith pair of legs is in the main features like Farran's figure, with the first basal segment 

 well distinguished, and with the second more or less well separated from the broad lamellar third 

 segment. The legs are generally asymmetrical, partly because the articulation is better developed on 

 the left than on the right side, and partly because the number of setae is rather variable. On the left 

 side we generally find a shorter terminal and a longer distal seta as figured by Farran, on the right 

 sometimes the terminal and sometimes the medial seta is absent, but often both are present. 



The anterior portion of the labruin is distinctly prominent in front; the anterior surface shows 

 a rather simple arrangement of the bristles (fig. 14 b) most similar to that of 5. obtusifrons, though 

 less complicated; in addition to the marginal rows of bristles an anterior transverse distinctly convex 

 row, composed of several units, and a posterior shorter one are observed. The oral surface of the labrum 

 has the anterior lateral group fairly well separated from the marginal rows (fig. 14 c); the posterior 

 groups of the longitudinal series are, as seen in figure, more or less fused. As seen in fig, the trans- 

 verse median groups are rather poorly developed. The structure of the "lamina labialis" etc. is in the 

 main like that of the preceding species. The arrangement of the hairs upon and behind the labial lobes 

 shows, as seen in fig. 14 b, a very marked difference between a central and two lateral groups. 



The intestine is not straight, but distintly twisted, at least vertically, though in a less degree 

 than in Lophothrix frontalis. 



The Ingolf-Expedition. III. 4. 2 7 



