EEPORT ON THE ANNELIDA. 
481 
perhaps, the somewhat finer tentacles. The posterior region has upwards of forty 
segments. 
The bristles present no feature distinctive from those of Station 47. The anterior 
hooks, however (PI. XXIXa. fig. 7), have a more abrupt distal dilatation than in the 
form just mentioned. The posterior uncini, on the other hand (PI. XXIXa. fig. 8), 
closely approach those of the American form. 
The greyish mud in the alimentary tract showed numerous Diatoms and sponge - 
spicules, but only a few Foraminifera. 
From the same Station (149 h — off Cumberland Bay), January 29, 1874, in 127 
fathoms, several examples occur which agree with the typical form from Norway, 
both in regard to anterior and posterior hooks. It is true there are slight differences 
in the curvature of the ventral lip anteriorly, but if such variations be allowed for 
separation of the species is unnecessary. 
Those from London Eiver had tubes of soft greyish mud. 
The contents of the intestine of this form agreed with the preceding, but no 
Foraminifera were visible. 
The soft greyish mud composing the tube of an example presented similar microscoj^ic 
features, the only additions being one or two minute Foraminifera and bristles of Annelids. 
The sections of the anterior third of this form, as in the other examples of Terehel- 
lides strcemi, are chiefly remarkable for the beauty and complexity (PI. XXXVIIIa. 
fig. 4) of the central apparatus. The hypodermic and muscular layers are compara- 
tively thin, and the united nerve-cords form a large mass in the ventral median line. 
The whole of the body -cavity of the region is occupied by the folds, seven or eight in 
number on each side. Each of the lamellae is double, a median septum indicating the 
apposition of the loops. The long folds are external, and the smaller are central and 
just above the area occupied by the gullet. Each loop is complete, that is, forms a 
continuous circuit, and it is the junction of the sides of adjoining loops that causes the 
septum and the double aspect. The ends of the flattened loops are, on the other hand, 
composed of a single fold. The whole apparatus resembles a series of branchial arches 
or the condition in Balanoglossus. The tissue has a firm external boundary, and 
consists of glandular substance arranged in a linear manner as in the alimentary lining. 
A section of the oesophageal region occurs in the middle of the folds a little above the 
ventral edge. 
Terebellidesf sp. (PL XXIXa. figs. 12, 13). 
Habitat. — Dredged at Station 169 (off the north-east point of the North Island of 
New Zealand),. July 10, 1874; lat. 37° 34' S., long. 179° 22' E. ; depth, 700 fathoms; 
bottom temperature 40°'0, surface temperature 58°'2 ; sea-bottom, blue mud. 
(ZOOL. CHALL. EXP. PART XXXIV. 1885.) 
LI 61 
