EXPLANATION OF THE PLATES. 



Plate I. 



Fig. i. Calanus hyperboreus Kroyer. 

 Fig. i a. f .. Marginal setae of the labrum ; x 77. 



1 b. f $. Oral surface of the labrum ; x 200. 



ic. f.. Lamina labialis etc. 1 = lamina labialis, s = serrula 6-dentata; x 200. 

 id. f . Lobi labiales and area behind, a c = articular cavities of the maxillulae, maxillae and 

 maxillipeds; x 44. 



Fig. 2. Macrocalanus princeps Brady. 

 Fig. 2 a. f $. Oral surface of the labrum; x 57. 



2 b. f$. Lamina labialis and anterior surface of the lobus labialis; x 57. 



Fig. 3. Megacalanus princeps Wolfendeu. 

 Fig. 33. f$. Labrum, lobi labiales and area behind from below; x 24. 



3 b. f$. Oral surface of the labrum; x 77. 



3 c. f ?. The lamina labialis, the lobi labiales and the right mandibula in ventral and partly anterior 



view, s == serrula 6-dentata; 1 == lamina labialis; x 57. 



3d. f$. The left maxilla; x 24. 



36. f $. The left second foot in anterior view, gl = glandular pores ; x 24. 



3 f . f ?. Se Re I pes II sin. in anterior view; 1 = lamina cribrosa; gl = glandular pore; x 44. 



3 g. f!j>. The lamina cribrosa; x 280. 



3 h. f <j>. The left fifth foot in anterior view ; x 24. 



3i. f c?. The segment 6 (VI) to segment n (XI) of left antennula; x 24. 



Fig. 4. Rhincalanus nasutus Giesbrecht 

 Fig. 4 a. Y$ (V). The anterior part of the body in left view; x 24. 



4 b. f $. The right side of the abdomen in abnormal specimen ; x 44. 

 4c. f $. The lamina labialis etc.; x 200. 



4d. f$. The fifth foot in abnormal specimen from Thor 1905 St. 88; x 90. 



4e. f c?. The oral surface of the labrum ; x 280. 



4f. f c?. The left antenna in posterior view; x 38. 



4g. f c?. The fifth foot in posterior view of specimen from Thor 1905 St. 88; x 90. 



4h. f c?. The fifth foot in posterior view of specimen (Nr. 2) from Thor 1905 St. 88; x 90. 



4i. f c?. The fifth foot in posterior view of specimen (Nr. 3); x 90. 



4 j. f c?. The fifth foot of an abnormal specimen from Thor St. 88; x 90. 



4k. YC? (V). The fifth foot in posterior view; x 90. 



4!. YC? (IV). The fifth pair of legs in posterior view of specimen from Thor 1905 St. 72; x 90. 



The Ingolf-Expedition. III. 4. 32 



