4:76 
THE VOYAGE OF H.M.S. CHALLENGER. 
diameter at their widest part. From the second Station an injured fragment of the 
anterior region, apparently of the same species, was obtained, and thus further information 
concerning the structure of the species was gained. 
The fragment of the anterior region somewhat resembles an example of the 
Ampharetidse from the great development of the lateral bristles, but the presence of a 
pair of branchiae with branched extremities is at variance with the features of this group. 
The cephalic region appears to be broad, with two rounded lateral masses and a central 
depression. The branchiae are narrower at the base than superiorly, the broad tip 
splitting into several short branches. The segments of the body seem to be narrow, 
judging from the closely approximated series of long pale golden bristle-tufts. The 
bristles (PI. XXVIIIa. fig. 26) lean rather to those of the Terebellidae than of the 
Ampharetidae, though there is less that is characteristic in them than in the hooks. Their 
shafts are straight, elongate, and often granular internally, apparently from a change iu 
the inner wall of the chitin. The tips are slightly curved, and furnished with rather well- 
developed wings below the very finely tapered extremities. The shorter forms show the 
latter feature best, but their wings are not more developed than in the longer forms. 
There are upwards of fourteen pairs in the specimen, and the series is incomplete. 
The fragments from Station 63 show that the posterior region of the body corre- 
sponds with that in the Terebellidae, but also has alliances with certain of the Ampharetidae, 
especially Gnibianella, since it is terminated by a distinct enlargement, about the length 
of three of the preceding segments. The anus, moreover, is surrounded by a series of 
long papillae, and two truncated processes occur on what seems to be the ventral surface, 
and which may have given origin to long styles. 
The hooks (PI. XXVIIIa. fig. 27) differ from those of any other known genus, 
combining certain of the characters of Melinna with those of Artacama. Two very 
distinct teeth occur above the great fang, and a third and fourth are partially seen 
superiorly. The great fang is very large, but the sinus beneath it is narrow^ The 
mucro in the latter is prominent, and the notch above the anterior inferior process is 
deep. The heel is slightly developed, and the ventral margin forms a uniform convexity. 
In the oesophagus of the example from Station 76 is a little greyish mud containing 
many minute Globigermce, a few fragments of sponge-spicules and Challengerice, Cocco- 
liths, and other debris. 
The specimens from Station 63 occurred in tubes having a tough, hyaline chitinous 
internal lining, and an external coat of grey mud, which dings with considerable tenacity 
to the former. The amorphous mud shows many fragments of silex, which cause 
translucent dots in the masses when viewed by transmitted light. It is possible that some 
of the rounded masses are connected with arenaceous Foraminifera, but this is uncertain. 
This form comes nearest Grubianella in regard to the anal enlargement. 
