22 



Eucalanus subtenuis Giesbrecht & Schmeil, 1898, p. 21. 



Eucalanus subtenuis Cleve, 1901, p. 7. 



Eucalanus subtenuis A. Scott, 1902, p. 401. 



Eucalanus subtenuis Thompson & Scott, 1903, p. 242. 



Eucalanus subtenuis Cleve, 1903, p. 363. 



Eucalanus subtenuis Cleve, 1904, p. 190. 



Eucalanus subtenuis Sars, 1905 (a), p. 2. 



Eucalanus subtenuis Wolfenden, I905(<?). p. 996. 



Eucalanus subtenuis Esterly, 1905, p. 135, fig. 9. 



Eucalanus subtennis appeared to have a fairly wide distribution in the area traversed 

 by the 'Siboga' as shewn by the following records. 



Stat. 47 ,J . — Stat. 66. — Stat. 75. -- Stat. 93. -- Stat. 98. — Stat. 118. - - Stat. 124. - 

 Stat. 125 (day). — Stat. 125 (night). — Stat. 129. —Stat. 136. — Stat. 138. — Stat. 141. - 

 Stat. 142. -- Stat. 144. — Stat. 157. — Stat. 165. — Stat. 169. — Stat. 172. — Stat. 184. — 

 Stat. 189". — Stats. 194 — 7. — Stat. 203 (surface). — Stat. 203 (1500 metres). — Stat. 204. — 

 Stat. 205. • Stat. 214. - - Stat. 215*. - - Stat. 217 (horizontal cylinder). — Statt. 220 

 (vertical net). — Stat. 245. 



Eucalanus suóleuuis has been recorded from the Atlantic, Pacific, and Indian Oceans 

 and also from the Arabian Sea. 



A considerable amount of care is necessary to distinguish the last three species of 

 Eucalamts from each other. The external characters are not very well marked, and the points 

 of difference are frequently obliterated when the specimens are distorted. It is always wise to 

 make dissections of the appendages before a definite conclusion is arrived at. 



7. Ettcalamts dcnlatus nov. sp. Plate II, figs. 1 — 8. 



Female — length 2,6 mm. 



The head is considerably contracted in front and is produced into a well-marked spiniform 

 process. When viewed from the side, the spiniform process appears to be directed slightly 

 upward, terminating in a sharp point, (Plate II, fig. 2). The fourth and fifth thoracic segments 

 are completely separated. The last thoracic segment has rounded extremities. The apex of the 

 last thoracic segment is greatly contracted and is very little wider than the base of the genital 

 segment. The abdomen is three-jointed and symmetrical, with one free segment between the 

 genital and anal segments. 



The antennules are twenty-three jointed, and extend beyond the end of the furca by 

 five joints. 



The antennae are nearly as in Eucalanus crassus. The proximal joint of the endopodite 

 is about doublé as long as broad. 



The mandible palp is furnished with two inner setae on the second joint of the basio- 

 podite. The first joint of the endopodite is destitute of setae, and the second joint is furnished 

 with four apical setae. The exopodite is apparently without segmentation, and is furnished with 

 six setae on the distal end. 



The maxillae and maxillipedes are nearly as in Eucalamts altcnuafus. The first and 

 second joints of the endopodite of the second maxillipedes are furnished with four setae. 



