EEPORT ON THE ANNELIDA. 
509 
Protula, Eisso. 
Protula capensis, n. sp, (PL LIV. fig. 2 ; PI. XXXIa. figs. 12, 13). 
Habitat . — Dredged at Station 142 (off tlie Cape of Good Hope), December 18, 1873 ; 
lat 35° 4' S., long. 18° 37' E. ; depth, 150 fathoms ; bottom temperature 47°'0, surface 
temperature 65°'5 ; sea-bottom, green sand. 
In the contracted spirit-specimen the length is 50 mm., and the diameter between 
the bases of the bristles in the thoracic region 6 ’5 mm. The transverse diameter of the 
posterior region at its widest part is 7 mm. 
The body is, as usual, divided into three very distinct regions, viz., the branchial, the 
thoracic, and the abdominal. 
The branchise form two great fan-shaped processes, which, when viewed internally, 
seem to spring from each side of a broad, flattened membranous lamella with a neatly 
rounded terminal margin, the superior or dorsal edge sending a free ridge over the bases 
of the branchise. It is the rounded ventral margin of this lamella that appears to turn in 
first when the fan is rolled up. The radioles are attached to the edge of the lamella to 
the number of about fifty-seven, and they are bound together by a web for some distance 
above the base. Externally the basal region of the fan (the apex being at the inferior or 
attached point) presents a smooth surface. Each radiole consists of a somewhat flexible 
axis with a large cavity, and, as usual, there does not appear to be any special development 
of a cartilaginous kind, at least to any extent, so as to render the radioles stiff. It accord- 
ingly shrivels up very much in Farrant’s solution, the transverse striation being apparently 
due to the structure of the hypoderm. Fixed in the tissues of the axis in one specimen, 
and quite visible under a lens, are many rounded granular bodies like ova, and some present 
a distinct egg-capsule. Whether these be parasitic ova or otherwise is yet an open 
question. They certainly do not move in the central canal, but are fixed. The tip of the 
radiole tapers to a filiform termination, a considerable part being free. The pinnae are 
closely set, commencing as short processes at the base, and again diminishing below the 
filiform tip. They seem to be proportionally stifier than the main stem. An opaque 
line runs along the bases of the pinnae, and probably indicates the position of the vessels. 
The margin of the truncated anterior region is bounded laterally by a continuation of 
the great lamella, which has a break at each side, but forms a continuous collar across 
the ventral aspect, and in the preparations this is reflected. There is thus a great 
contrast between the ventral border in this group and that in the Sabellidm. In the 
cavity of the branchial fan were fsecal pellets, mud, and Foraminifera. 
The only representative of the tentacle is a double fold of the basibranchial lamella at 
the dorsal edge. 
