REPOET OK THE AKKELIDA. 
16 ;^ 
Nephthys verrilli, n. sp. (PL XXVI. figs. 6, 7 ; PI. XXXIIa. fig. 8). 
Habitat . — Dredged at Station 167 a (Queen Charlotte Sound), June 27, 1874; 
lat. 41° 4' S., long. 174° 19' E.; depth, 10 fathoms ; surface temperature, 51°'5 ; sea- 
bottom, mud. 
A comparatively small species, the examples measuring about 14 mm. in length, and 
havina: a diameter of 2 '5 mm. 
The head (PL XXVI. fig. 6) is considerably elongated from before backward, and has 
near the posterior border a pair of small black eyes. The tentacula and subtentacula are 
proportionally large. In extrusion the proboscis (fig. 7) presents twenty-two rows of 
papillse, which diminish from the distal region to the base. There are eleven distal 
papillae, the median dorsal being single, while the median ventral is laterally bifid 
instead of radially, as in the others. 
The foot (PL XXXIIa. fig. 8) bears superiorly a moderate lamella, which has a greater 
horizontal than a vertical diameter. It is less erect than in Nephthys dibranchis, Grube, 
and its external (or inferior) curve is longer. The cirrus at the base of the branchia has 
a larger basal and a more slender distal region than in the latter. The branchia has a 
basal protuberance externally, is proportionally large, and coiled inward. The ventral lobe 
has superiorly a small branchia, which is often curved inward. A bluntly conical lamella 
occupies the space between the latter and the ventral cirrus, and the arrangement thus 
differs from that in Nephthys dibranchis. The ventral cirrus is expanded interiorly and 
tapered distally. The superior and inferior bristles are long and finely tapered, and they 
likewise have a well-marked curve. In the inferior series there are many shorter and 
less attenuate forms with bold curves. The short barred bristles show no distinctive 
features. 
Though thus widely differing in habitat, this species closely approaches Nephthys 
dibranchis from the Arafura Sea. 
In transverse section the nerve-cords are found to be enveloped even more closely 
than in Nephthys dibranchis, Grube, and they appear to be proportionally smaller. 
The cuticle is comparatively thick, but the hypoderm is slightly developed. No 
neural canal is visible. The ventral longitudinal muscles are bilobed in section, each 
side forming an ovoid mass of muscle. The proboscis and other parts follow the 
typical structure. 
This form somewhat approaches the Nephthys atlantica of Hansen^ from the North 
Atlantic, but it is readily distinguished both from this and the new species {Nephthys 
minuta) described by Theel ^ from the Kara Sea, by the presence of the inferior branchia. 
1 Den norske Nordhavs-Exped., p. .31, pi. iv. figs. 1, 2. 
2 Ann el. des mers Nonvelle-Zemble, p. 28. 
