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joint of the left exopodite is distinctly notched. The apical spines are short and stout. The 
longer one is considerably shorter than the joint (Plate XLIV, fig. 17). 
The rounded last thoracic segment, and the long furcal joints readily separate this form 
from any of the other known species. 
The female described by Esterty as Avzete//us major appears to be identical with Sars’ 
Arietellus simplex. The figure of the fifth foot given by Esreriy, and reproduced in this 
report, shews the apical spine of the second free joint to be very short. It is only about equal 
to one-half of the length of the joint. 
Genus Paraugaptilus Wolfenden, 1904. 
This genus was established by WoLFENDEN in 1904, for a form found in the warm area 
of the North Atlantic, that appeared to be closely related to Augaptilus and Arietellus. Sars 
(1907a@) recorded WoLFENDEN’s type species from the plankton collected by the Prince of Monaco, 
but placed it under the genus Arzete/lus. VAN BREEMEN, however, regards the genus as distinct 
and restores it in ‘Nordisches Plankton’ 1908. This genus appears to be more closely related 
to Arzetellus than to Augaptelus. | have therefore included in under the Family Arietellidae. 
The two sexes are readily separated from either Augaptelus or Arzetellus, by the structure 
of the fifth pair of feet. The fifth pair of the female is rudimentary. Each foot is composed 
of a single joint. The male fifth pair is well developed and prehensile. The right and left 
feet are not symmetrical. The basiopodite is two-jointed. The exopodite of each foot is two- 
jointed. The endopodite is very small. It is apparently two-jointed. 
Males and females of a form closely related to the type of the genus were obtained 
from the plankton collected by the ‘Siboga’ in the Malay Archipelago. 
1. Paraugaptilus similis nov. sp. Plate XLIII, figs. 11—r19. 
Female — length 3,75 mm. 
Viewed from above, the body appears ovate and robust. The forehead is considerably 
contracted in front. The posterior margins of the last thoracic segment are broadly rounded. 
The segment is furnished with a small tooth on each side of the junction with the abdomen. 
Seen from the side, the dorsal surface of the cephalic segment is much depressed, and the 
forehead is very narrowly rounded. The ventral margin of the last thoracic segment is boldly 
rounded. The distal end is hollowed out. It is produced into a small tooth at the upper angle, 
where it joins the dorsal line (Plate XLIII, fig. 13). The dorsal and lateral surfaces of the 
thoracic segments, are clothed with fine short hairs as shewn in the figures. The rostrum is 
represented by two slender filaments. 
The abdomen is composed of four segments. The combined length of the abdomen 
and furca is contained two and a half times in the total length of the cephalothorax, from 
the frontal margin to the base of the genital segment. The genital segment is moderately large. 
It is distinctly inflated on each side. The lateral surface is furnished with a small, dorsally 
directed pointed process. The genital opening is provided with a pointed knob (Plate XLIII, 
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