REPORT ON THE ANNELIDA. 
463 
layer of soft greyish mud. The latter shows swarms of Diatoms, a few Racliolarians, and 
somewhat coarser sand-particles than occur in the alimentary canal. 
In this genus the nerve-cords seem to follow a similar arrangement to those in Pista. 
In the present species the body-wall has powerful oblique muscles, which are inserted 
outside the nerve-area. The perivisceral chamber contains many ova. 
Lecena langerhansi,^ n. sp. (PI. XXVIIIa. fig. 12). 
Habitat. — Trawled at Station 168 (off the east coast of the North Island, New 
Zealand), July 8, 1874; lat. 40° 28' S., long. 177°' 43' E.; depth, 1100 fathoms; 
bottom temperature 37°‘2, surface temperature 57°’2 ; sea-bottom, blue mud. 
The fragmentary example measures about 9 mm. in length and barely 1 mm. in diameter. 
In the general form of the body it agrees with Lecena neo-zealanice from the same 
site, and it seems to have similar tongue-shaped processes on the post -cephalic region 
of the dorsum ; but as rupture with softening had occurred in the specimen, it would be 
unsafe to define minutely. 
So far as can be ascertained, twelve pairs of bristle-bundles exist. The extremities 
of these closely resemble those of the other species, e.g., Lecencc antarctica, the shorter 
series, perhaps, having less expanded wings. 
The hooks (PL XXA^IIIa. fig. 12) are small, and diverge from any of the preceding. 
The crown is of moderate height, with five teeth above the great fang. The curves on 
each side of the mucro below the latter are pronounced, and the ventral line is convex. 
The dorsal (or posterior) outline is tolerably straight above the heel. With the 
exception of the difference in the length of the crown the structure of the hook most 
nearly approaches that of Lecena neo-zealanice. It is not yet known how far sexual 
distinctions affect the hooks, so that the position of this form is uncertain. 
In transverse section the hypoderm presents a thick layer ventrally. The circular 
muscular coat is of great strength. The longitudinal muscles, both dorsal and ventral, 
are compact and massive. The oblique are likewise well developed. 
Lanassa, Malmgren. 
Lanassa sarsi,^ n. sp. (PI. XXVIIIa. figs. 4, 5). 
Habitat. — Dredged at Station 169 (off the north-east point of the North Island, 
New Zealand), July 10, 1874; lat. 37° 34' S., long. 179° 22' E.; depth, 700 fatnoms ; 
bottom temperature 40°‘0, surface temperature 58°’2 ; sea-bottom, blue mud. 
1 After Prof. Paul Langerhans of Freiburg, and Physician in Madeira, who has done much valuable work amongst 
the Annelids of Madeira. 
2 After the late Prof. M. Sars. 
