LS 
Augaptilus longicaudatus Wolfenden, 1904, p. 112. 
Augaptilus longicaudatus Sars, 1905 (0), p. 4. 
Augaptilus longicaudatus Esterly, 1905, p. 188, fig. 41. 
Augaptilus longicaudatus Pearson, 1906, p. 28. 
Augaptilus longicaudatus Farran, 1908, p. 78. 
Augaptilus longicaudatus van Breemen, 1908, p. 135, fig. 154. 
Six specimens of this form were found in the plankton collected with the HENSEN vertical 
net at the following stations. 
Stat. 185 (1536 metres to surface), 3 specimens. — Stat. 203 (1500 metres to surface), 2 spe- 
cimens. — Stat. 276 (750 metres to surface), I specimen. 
Augaptilus longicaudatus can be distinguished from the other members of the genus, 
by its moderately long abdomen and furcal joints. It is closely related to Augaptilus hecticus 
and Augaptilus megalurus. \t differs from the former species, by the furcal joints being five 
times longer than broad, and from the latter, by the equal length of the second and third 
abdominal segments. In Augaptilus hecticus the furcal joints are three times longer than broad. 
The third abdominal segment of Augaptilus megalurus is distinctly shorter than the second segment. 
This species appears to have a moderately wide distribution. 
5. Augaptilus palumbor Giesbrecht. 
Augaptilus palumbot Giesbrecht, 1880, p. 813. 
Augaptilus palumbozt Giesbrecht, 1893, p. 400, pls. 27, 28 & 39. 
Augaptilus palumboi Giesbrecht & Schmeil, 1898, p. 122. 
Augaptilus palumbot 1. C. Thompson, 1903, p. 28. 
Augaptilus palumbot Sars, 1905 (0), p. 4. 
Augaptilus palumbot Farran, 1908, p. 75. 
Augaptilus palumboi van Breemen, 1908, p. 134, fig. 151. 
Eight specimens of this species were found in the plankton collected with the HENsEN 
vertical net at the following stations. 
Stat. 118 (goo metres to surface), I specimen. — Stat. 128 (700 metres to surface), I spe- 
cimen. — Stat. 141 (1500 metres to surface), I specimen. — Stat. 143 (1000 metres to 
surface), 2 specimens. — Stat. 148 (1000 metres to surface), I specimen. — Stat. 203 (1500 
metres to surface), 2 specimens. 
Augaptilus palumbot is readily distinguished by its small size, by the short second 
abdominal segment, and by the anal segment being twice the length of the second segment. 
This species was originally found in the Pacific Ocean. It has been recorded within 
recent years from the North Atlantic. 
6. Augaptilus placttus nov. sp. Plate XLII, figs. 1o—19. 
Female — length 10 mm. 
Seen from above, the body is elongate ovate, and rather slender. The last thoracic 
segment is contracted posteriorly, and the distal ends are somewhat narrowly rounded. Viewed 
137 : 
SIBOGA-EXPEDITIE XXIX@. 18 
