442 
THE VOYAGE OF H.M.S. CHALLENGER. 
A comparatively large form, the fragments measuring about 35 mm. in length, and 
having a diameter anteriorly of 3 mm. The specimen is so softened that a detailed 
description would be unsafe. 
The snout does not seem to be much produced in front, but it is injured and the 
proboscis protrudes. The branchise are four in number, and are arranged somewhat as in 
Melinna, a slight ridge apparently running backward from the posterior pair. They^seem 
to be proportionally shorter than in Melinna. No dorsal hooks are visible. 
There is a somewhat triangular space behind the bases of the branchiae on the dorsum, 
but no trace of the fimbriated and free edge of the fourth bristled segment, as in 
Melinna. The arrangement of the lateral regions resembles that in the latter form. 
Fourteen pairs of bristle-bundles occur on each side. These are somewhat shorter than 
in Melinna, with finely tapered tips. 
The uncini (PI. XXVIIa. fig. 18) most nearly approach those of Melinna, an interest- 
ing fact, for the number of the bristle-bundles and the arrangement of other parts 
diverge, moreover, in the new form the fimbriated border of the fourth bristled segment is 
wholly absent. In the hook the general outline is similar, but there are three teeth 
above the great fang in most cases, and the curvatures of the accessory fang and the 
anterior inferior process differ. 
The greyish mud in the intestine showed a few Globigerinw and other Foraminifera, 
Diatoms, and fragments of minute Crustacea. 
The tube forms a somewhat stiff cylinder, having a chitinous lining of the usual 
character, coated externally with fine greyish mud, in which are many Foraminifera. 
Moreover, since numerous examples, such as Polystomella, of the latter have only their 
edges projecting, a peculiarly granular condition of the surface is caused. 
Family Teeebellida;. 
The number of species and varieties procured in the Challenger Expedition seems to 
be greater than in any former voyage. Thus Schmarda describes fourteen species (one 
of which is doubtful), and the majority of these are littoral forms. The Sabellides 
oligocirra of this author appears to be allied to Thelegms, and so with his Terebella 
macrocephala. Kinberg gives twenty- three, one or two of which had previously been 
known. Grube in the collection of the “ Gazelle ” mentions seven, and in the Philippine 
Annelids sixteen. Four occur in his Annulata CErstediana. In the collection made by 
the “ Porcupine,” Ehlers found six species, and of these one {Amphitrite) came from a 
depth of 1380 fathoms. 
The number requiring separate notice in the Challenger collection is about thirty-six, 
and several of these are of very great interest. The fine distinctions, moreover, existing 
