EXPLANATION OF THE PLATES. 



Plate I. 



Fig. i. Calanus hyperboreus Kroyer. 

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



— ib. f $. Oral surface of the labrum ; x 200. 



— 1 c. f<j>. 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 <j>. Oral surface of the labrum; x 57. 



— 2 b. f<j>. Lamina labialis and anterior surface of the lobus labialis; x 57. 



Fig. 3. Megacalanus princeps Wolfenden. 

 Fig. 3 a. f<j>. Labrum, lobi labiales and area behind from below; x 24. 



— 3b. f<j>. Oral surface of the labrum; x 77. 



— 3 c. f <j?. 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 <j>. The left maxilla ; x 24. 



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



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



— 3 g. f$. The lamina cribrosa; x 280. 



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



— 3 i. f o*. The segment 6 (VI) to segment 11 (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. 



— 4b. f<j>. The right side of the abdomen in abnormal specimen; x 44. 



— 4c. f<j>. The lamina labialis etc.; x 200. 



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

 — ■ 4 e. f 0*. The oral surface of the labrum ; x 280. 



— 4! f o*. The left antenna in posterior view; x 38. 



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



— 4h. f J 1 - The fifth foot in posterior view of specimen (Nr. 2) from Thor 1905 St. 88; x 90. 



— 4L f o*. The fifth foot in posterior view of specimen (Nr. 3); x 90. 



— 4j. f o*. The fifth foot of an abnormal specimen from Thor St. 88; x 90. 



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



— 4I. Yd* (IV). The fifth pair of legs in posterior view of specimen from Thor 1905 St. 72; x 90. 



The Ingolf-Expedition. III. 4. -J 



