BISPIRA VOLUTACORNIS. 257 
1865. Sabella volutacornis, Johnston. Cat. Worms. Brit. Mus., p. 262. 
» Diastylia 5 De Quatrefages. Annel., 1, p. 421, pl. xv, figs. 5—7. 
1867. Sabella - Parfitt. Cat. Annel. Devon, p. 34. 
1870. of (Distylia) volutacornis, Grube. Arch. f. Naturges., p. 336. 
1893. Bispira Marie, n.s., Lio Bianco. Atti R. Accad. Sc. Nap., vol. v, No. 11, p. 75, Tav. i, fig. 2, 
Tav. u, fig. 4, Tav. i, fig. 7. 
1894. ay volutacornis, De St. Joseph. Ann. Se. nat., 7° sév., t. xvii, p. 286, pl. xi, figs. 289—295 
1904. i! . Journ. M. B. A., vol. vu, p. 232. 
1906. a Bohn. Ann. Sc. nat., 9° sér., t. iu, p. 130: 
1915. Pa . Allen. Journ. M. B. A., vol. x, p. 642. 
1916. is on McIntosh. Ann. Nat. Hist., ser. 8, vol. xvi, p. 20. 
NOM, e i Rioja. Anél. Polig. Cantab., p. 62. 
Habitat —First found in South Devon (Montagu); Falmouth; in a muddy tube in a 
chink of a rock near low water mark, St. Peter Port, Guernsey, and under a stone between 
tide marks, Herm (W. C. M.). Plymouth (Allen). Not uncommon on the southern shores, 
and represented in Leach’s collection in the British Museum. Abroad it has been met with 
at Bréhat, Dinard (De St. Joseph) ; shores of Cantabria (Rioja). 
In the livmg form the dorsal groove presents a white bar at the edge of the 
collar, and a brown fillet occurs at each side and passes under the large ventro-lateral 
brown flaps bordered with white (Plate CXIII, fig. 5), the dorsal edges of which 
are continuous with a slight ridge on each side of the anterior region, the ridge being 
above a deep furrow which leads from above downward to the mouth. Ventrally 
the deep purplish-brown collar with its border of pure white stretches continuously 
across till it passes in front of the lateral flap. Dorsally and ventrally the anterior 
region is somewhat paler than the rest, the lateral region, however, being slightly darker, 
as indeed it is all the way backward till near the tip of the tail. Ventrally the scutes 
are buff (pale brownish) and marked by the copragogue, which turns to the right at the 
posterior border of the anterior region and passes dorsally. In an example the segment in 
front ventrally was entire, but the next in front was split as if it had a copragogue of its 
own. Young forms are pale greenish, the branchiz being pale, and only a little border of 
white and a few touches of brown are visible ventrally at the collar, which has a deep median 
fissure. Dorsally none of these hues are present, the rudimentary flaps being pale. The 
great development and pigmentation of these flaps is an adult feature. 
When the branchiz are removed from the cephalic plate, the dorsal groove abuts on 
two semicircles of firm chordoid tissue which pass downward to the sides of the mouth. From 
the groove a firm process of similar tissue passes straight downward and bifurcates after a 
short course, its summit giving origin to two short curved flaps, like a bifid epistome, over- 
hanging the mouth, which appears as a triradiate fissure with two pouting membranous 
lobes inferiorly. By the sides of the dorsal groove are two thick, firm ridges, apparently 
fused with the basal chordoid semicircles supporting the branchiz. From the outer base 
of each of these the collar arises by a thick circular flap, from which the large lateral division 
passes forward and downward to end in a smaller thick attachment at the side of the anterior 
process of the first scute (Plate CXITI, fig. 5). This lateral flap is slightly tinted in the prepara- 
tions, but in the living form is of the same deep violet-brown bordered with white. Over- 
lapping the ventral edge of this lamella is the ventral plate, which curves downward and 
