232 
THE VOYAGE OF H.M.S. CHALLENGER. 
elements from the latter locality showing large confluent eyes. Kinherg met with several, 
but none appear to have been found by Schmarda. Most of those described up to this 
time may with propriety be placed under the original genus ; but, for instance, the species 
from North Uist in the Outer Hebrides may bear the late Prof. Keferstein’s name 
Prionognathus,^ since it differs from Staurocephalus in the absence of the distal arti- 
culation to the dorsal cirrus, and other particulars. In regard to this point, there- 
fore, I would differ from the opinion of my late esteemed friend Prof. Grube, who 
grouped them all under the single genus Staurocephalus in his comparatively recent 
resume.^ 
The occurrence of a species of this group at a depth of 1000 fathoms is noteworthy, 
for hitherto they have generally been procured in shallow water or the littoral zone. 
Staurocephalus, Grube. 
Staurocephalus australiensis, n. sp. (PI. XXXVI. fig. 6 ; PI. XVIIIa. figs. 9, 10). 
Habitat. — Dredged at Station 162 (off East Moncoeur Island, Bass Strait), April 2, 
1874; lat. 39° 10' 30" S., long. 146° 37' E. ; depth, 38 fathoms; surface temperature, 
63° '2 ; sea-bottom, sand and shells. This Station seemed to be rich in peculiar forms. 
The specimen represented the posterior region of a large example of the genus, and 
is distinguished by its great flattened dorsal cirri (which presented an analogy with the 
peculiarly flattened dorsal cirri of Polynoe platycirrus from the same region). 
The fragment is about 1 1 mm. in length, and its transverse diameter in front is about 
5 mm. The dorsal surface is rounded, the ventral somewhat flattened, and grooved in 
the middle line. It tapers rather abruptly posteriorly, and has the usual deflnitely 
marked segments characteristic of the genus. 
One of the most conspicuous features is the great size of the dorsal cirri, which, spring- 
ing from the base of the foot dorsally, extend considerably beyond its tip. The terminal 
segment of the process is well marked, and many show a slight enlargement below it. 
In the interior of the cirrus is a slender tapering spine, which trends from the great spine 
of the foot near its base. 
Superiorly the free edge of the foot presents two prominent mamillse, between 
which the bristles of the region emerge. The upper series consists of a few 
slender tapering bristles, flattened towards the tip, and one or two shorter and less 
attenuate forms inferiorly. The latter also present a distinct notch at the extremity 
(PI. XVIIIa. fig. 9). Both groups are comparatively short when contrasted with those 
of Prionognathus, 
1 Prionognathus kefersteini, M‘I., Trans. Roy. Soc. Edin., xxv. p. 417, 1869. 
2 Jahres-Bericht der Schles. Gesellsch.f. vat. Gultur, 1878, p. 109 et seq. 
