i8 



Stat. 19, 2 specimens. — Stat. 35, 3 specimens. — Stat. 36, 3 specimens. — Stat. IJ, 15 

 specimens. - - Stat. 40. — Stat. 66, 5 specimens. — Stat. 75, 16 specimens. — Stat. 81, 

 4 specimens. ■ — Stat. 93, 7 specimens. — Stat. 96 (day). — Stat. 96 (night). — Stat. 98, 

 20 specimens. — Stat. 99. — Stat. 106. — Stat. 1 10, 3 specimens. — Stat. 112,3 specimens. — 

 Stat. H7 a . — Stat. 118, 5 specimens. — Stat. 124, 15 specimens. — Stat. 125. — Stat. 128.- 

 Stat. 129, 3 specimens. — Stat. 133. — Stat. 136, 75 specimens. — Stat. 138, 90 specimens. — 

 Stat. 144. — Stat. 146. — Stat. 148, 8 specimens. — Stat. 149. — Stat. 157. -- Stat. 165, 

 33 specimens. — Stat. 168, 3 specimens. — Stat. 169, 46 specimens. — Stat. 172. — 

 Stat. 177". — Stat. 184, 65 specimens. — Stat. 185. — Stat. 186, 8 specimens. — Stat. 

 189% 10 specimens. — Stat. 193, 8 specimens. Stat. 203 (surface), 2 specimens. — 



Stat. 203 (1500 metres), 8 specimens. — Stat. 204, 25 specimens. — Stat. 205, 10 specimens. — 

 Stat. 210°, 15 specimens. — Stat. 213, 15 specimens. — Stat. 214. — Stat. 215% 50 

 specimens. — Stat. 216. — Stat. 217 (horizontal cylinder), 100 specimens. - Stat. 220 

 (vertical net), 8 specimens. — Stat. 220 (surface), 15 specimens. — Stat. 223, 3 specimens. — 

 Stat. 224, 7 specimens. — Stat. 225, 5 specimens. — Stat. 229, 10 specimens. — Stat. 

 243, 10 specimens. — Stat. 245, 5 specimens. — Stat. 276. — Stat. 282, 11 specimens. — 

 Stat. 304. 



The peculiar projection of the last thoracic segment, and the row of fine spines at the 

 distal end of the abdominal segments, help to identify the females of this species from Undi7iula 

 vulgaris, and the peculiar form of the exopodite of the left fifth foot, renders the identification 

 of the males comparatively simple. The endopodite of the male left fifth foot is rudimentary, 

 and consists of a single small joint. Some care has to be taken in separating the male of 

 Undinula darwini, from that of Undinula caroli, as the exopodite of the left fifth foot of the 

 two species has a very similar structure. 



3. Undinula caroli (Giesbrecht). 



Calanus caroli Giesbrecht, 1888, p. 331. 



Calanus caroli Giesbrecht, 1893, p. 91, pi. 8, fig. 36. 



Calanus caroli Giesbrecht & Schmeil, 1898, p. 17. 



Calanus caroli Wolfenden, 1895(0), p. 994, pi. XCVII, fig. 41. 



This species although widely distributed throughout the area traversed by the 'Siboga' 

 appeared to be comparatively rare. The following are the stations where it was noted. 



Stat. 2i7> 2 specimens. — Stat. 75, 2 specimens. — Stat. 93, 1 specimen. — Stat. 98, 2 

 specimens. — Stat. 124. — Stat. 136, 2 specimens. — Stat. 138, 5 specimens. — Stat. 148, 

 2 specimens. — Stat. 165, 4 specimens. — Stat. 186, 1 specimen. — Stat. 210% 1 specimen. — 

 Stat. 217 (horizontal cylinder), 1 specimen. — Stat. 220, 1 specimen. 



The difficulty in distinguishing this .species from Undinula darzvini, is no doubt the cause 

 of the paucity of records since it was established by Giesbrecht. Wolfenden is apparently 

 doubtful that it is really distinct from Undinula darwini. It must be admitted, that considerable 

 care is necessary to make out the species when mixed up with Undinula darwini, but when 

 the difference is once seen, further identification is comparatively easy. The position of the tooth 

 on the inner edge of the external spine, which is part of the last joint of the exopodite of the 

 left fifth foot, is the specific character separating the two species. In Undinula caroli, the tooth 

 is placed about one-sixth from the base of the spine, and five-sixths from the distal end. The 



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