390 
THE YOYAGE OF H.M.S. CHALLENGER. 
slight diminution of the neck occurs a short distance below the wing, then it gradually 
increases to the shoulder, and again narrows interiorly. The shoulder is less abrupt 
than in Notomastus sarsii and even than in Eunotomastus grubei. 
The sandy mud in the intestine of those from Station 49 contained many minute 
Diatoms, a few sponge-spicules, and fragments of Eadiolarians. 
In section this differs from the British representative in the less numerous and more 
massive divisions into which the great longitudinal muscles are separated. The ventral 
are especially large. The fibrils are also much coarser. The inner surface of the 
muscular bundles is covered by a thick though translucent sarcolemma, which may have 
some influence in retaining them in position. 'Fhe alimentary canal and nerve-area 
occupy the same position. 
Prof. Verrill’s^ descriptions of Notomastus luridvs and Notomastus JiUformis are not 
sufficiently exact to give certainty in diagnosis, so that it is possible the above may be 
connected with either. 
Notomastus (?) sp. 
Habitat. — A variety was dredged at Station 149h, off Cumberland Bay, Kerguelen; 
lat. 48° 45' S., long. 69° 14' E. ; depth, 127 fathoms; surface temperature, 39°’8 ; 
sea-bottom, volcanic mud. 
In external appearance (PI. XLVI. fig. 2) it corresponds with the ordinary British 
form, and also in regard to the structure of the bristles and hooks, as well as of the 
proboscidian papillae. The dorsal lamellae of the second region of the body, however, 
are larger. It likewise is only a fragment, consisting of the snout and eight or nine 
segments behind the bristles. No eyes are visible. 
In minute anatomy this form closely agrees with the common British species. No 
neural canal, however, is visible, but, as the specimen is small, this feature is not one on 
which much reliance need be placed. The genus Notomastus probably agrees with 
Ai 'enia, De Quatrefages.*'^ 
Dasybranchus, Grube. 
Dasybranchus (?) sp. (PL XLV. figs. 13, 14 ; PI. XXIVa. fig. 17). 
Habitat — Trawled at Station 233b (south of Yedo, Japan), May 26, 1875; lat. 
34° 18' N., long. 133° 35' E.; depth, 15 fathoms ; surface temperature, 66°‘3 ; sea-bottom, 
blue mud. 
A headless fragment, evidently of a large species, which measures about 40 mm. in 
length and 6 mm. in breadth. 
1 Kept. Invert. An. Vineyard Sound, pp. 610, 611. 
2 Anneles, p. 250. 
