REPOET ON THE ANNELIDA. 
465 
lamella. The snout presents the usual horse-shoe curve of the tentacular fold over 
the mouth, and beneath the latter a short crenated ridge, in front of the papillose 
one just mentioned. The two other lateral lamellae converge to an elevated 
region which becomes continuous with a ventral ridge immediately behind the fore- 
going. The first bristle -papilla springs from the uj)per angle of the third lamella 
(fourth segment), and thus corresponds with the ordinary arrangement in Lanassa. 
Fifteen pairs of bristle-tufts are present in the specimen, but as it is ruptured at the 
fifteenth the number is uncertain. The bristles (PI. XX VIII a. fig. 6) agree in 
structure with the generic type, presenting a straight shaft, a slightly bent winged 
region, and a long delicately tapered point, minutely serrated on one edge. Those 
of the shorter series in each tuft have somewhat shorter and broader (well-developed) 
wings. 
The hooks (PI. XXVIIIa. fig. 7) are much larger than in the preceding forms, and 
while the crown shows ten or eleven teeth above the great fang, it is less obtuse than 
in these. A long process occurs at the posterior inferior angle after the manner 
of that in Pista and Eupista. The region from the base of the great fang to 
the anterior inferior projection is large, much larger in proportion than in the foregoing 
species. 
In the fine mud occupying the posterior end of the fragmentary alimentary canal 
are many minute Glohigerince, a fine Cliallengeria, minute triradiate points (minute 
Pteropods ?), a few Diatoms and Coccoliths. 
Euthelepus, n. gen. 
Euthelepus setuhalensis, n. sp. (PI. L. fig. 4 ; PI. XXVIIIa. fig. 13). 
Habitat. — Dredged at Station II. (off Setubal, Portugal), January 13, 1873 ; lat. 
38° 10' N., long. 9° 14' W. ; depth, 470 fathoms; surface tem 2 :)erature, 57°'0 ; sea- 
bottom, green mud. 
The anterior region of a small form, measuring about 12 mm. in length, or with the 
tentacles and branchiae 4 or 5 mm. more, and having a diameter of 1-8 mm. 
It is easily distinguished from any of its congeners by possessing the habit of a 
Thelepus, and the branchiae of one of the Ampharetidae. The bristles and hooks are also 
characteristic. 
The cephalic lobe is truncated anteriorly and furnished with a rim posteriorly as in 
Thelepus, and it gives rise to a series of tentacles which are similarly grooved and 
crenated, though they do not appear to attain the dimensions exhibited by the form 
just mentioned. No ocular specks are visible. The buccal segment j:)resents a frilled 
(ZOOL. CHALL. EXP.— PART XXXIV. 1885.) LI 59 
