REPORT ON THE ANNELIDA. 
435 
Samythopsis, n. gen. 
Samythopsis grubei, ii. sp. (PI. XLVIII. fig. 3 ; PL XXVIIa. fig. 8). 
Habitat. — Trawled at Station 298 (off the American coast, south of Valparaiso), 
November 17, 1875 ; lat. 34° 1 ' S., long. 73° 56' W.; depth, 2225 fathoms ; bottom 
temperature 35° ’6, surface temperature 59°'0 ; sea-bottom, blue mud. 
A form of moderate size, measuring about 28 mm. in length, and having a diameter 
of 2 '5 mm. at its widest part in front. The spirit had not reached the specimens very 
thoroughly, since they were enclosed in their tubes. 
The cephalic lobe is subquadrangular, with a prominent papilla at each angle 
anteriorly. Numerous smooth tentacles occur beneath the frontal lobe, and in one 
specimen very much longer tentacles are present in the middle line ; and it is possible 
others exist in the perfect animal. The mouth opens immediately below the latter, at 
the anterior border of the narrow cephalic region, which has before it the frontal arch, 
then the cephalic lobe with two ridges posteriorly. The cephalic region is separated from 
the rest of the body, both dorsally and ventrally, by a prominent nuchal fold, which is 
notched on each side in front of the first bristle-tuft. The dorsal surface of the body is 
convex throughout, the ventral flattened anteriorly, and grooved posteriorly. In addition, 
the anterior (or thoracic) region, i.e., the ‘division bearing the bristles, is marked by 
prominent, thickened ridges, somewhat lighter in colour than tlie rest of the body. 
There are seventeen. pairs of bristle-bundles, the first l:>eing considerably elongated. The 
wings of the bristles are feebly developed, and the tip is slightly curved and finely 
tapered. 
As in Samyiha the uncini commence on the fourth bristled segment, and extend to 
the tip of the tail. In front the pads occur below the setigerous processes, and behind 
the transverse thickened bands which characterise the anterior region. In the posterior 
division they are situated at the base of the long cirri peculiar to this part. Above the 
latter is a short dorsal process. The crown of the hooks (PI. XXVIIa. fig. 8) is elongated, 
and the dental edge shows six teeth, the inferior being considerably larger than the 
adjoining. A prominent intermediate process occurs between the last tooth and the 
anterior inferior projection. In its general outline the hook approaches that of Amphicteis, 
especially in the marked inflection of the dorsal margin, but it more closely resembles 
Samytha in dentition. 
The cirri along the posterior region are characteristic. Just before the anal enlarge- 
ment is reached they become considerably shorter, and the first on that region is short, 
flattened, and somewhat clavate in outline, while the second is almost globular. They 
are absent in the o>her segments. A short and slightly tapered cirrus occurs on each side 
