EXPLANATION OF THE PLATES. 



Plate I. 



Fig. I. Calanus hyperboreus Kroyer. 

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



— lb. f 5. Oral surface of the labrum ; x 200. 



— I c. 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 Wolfenden. 

 Fig. 3 a. 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. 



— 3 e. 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; > 44. 



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



— 3 h. f $. The left fifth foot in anterior view; x 24. 



— 31 f c?. 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. 



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



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



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



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



— 4 f. 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. Y<^ (V). The fifth foot in posterior view; x 90. 



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



The Ingolf-Expedition. III. 4. - 



