434 MYSTIDES ELONGATA. 
preserved examples—the cirri being especially tinted. The third segment has no dorsal 
cirri. Dorsal and ventral cirri of the following segments are round or broadly oval. Anal 
segment with two large oval cirri, and between them a short papilla. Bristles have shafts 
with enlarged ends, and two long, equal spinous processes or claws; the terminal blade is 
long, slender, minutely serrated and obliquely striated. 
SYNONYMS. 
1878. Mystides borealis, Théel. Annél. Nouv. Zemb., p. 35, pl. u, figs. 29—32. 
1880. - ceca, Langerhans. Zeitschr. f. wiss. Zool., Bd. xxxii, p. 310, Taf. xvi, fig. 42. 
1887. Se viridis, Webster and Benedict. U.S. Com. F. and F., p. 712, figs. 10—12. 
1913. *: ceca, Fauvel. Polych. Bull. Instit. Oceanogr., No. 270, p. 53. 
1914. S borealis, Southern. Proc. Roy. Irish Acad., vol. xxxi, No. 47, p. 72, pl. viii, 
figs. 19 a—p. 
1921. a ie McIntosh. Ann. Nat. Hist., ser. 9, vol. vin, p. 298. 
Habitat—Dredeed at 24 fathoms in Clew Bay on sand and shells, and on similar ground 
off Dingle Bay in 78 fathoms (Southern). 
Distribution —Nova Zembla; Madeira (Langerhans); Monaco (Fauvel); Hastport, 
Maine (Webster and Benedict). 
This is another of the minute examples (5$ mm. long) of the genus which can be best 
studied in the living condition, and it is possible that revision may alter certain of the 
views at present held. Southern’s careful descriptions, however, will aid materially in 
their elucidation. The broadly oval cirri of this form are conspicuous. The bristles are 
slender and of moderate length (Plate CX XXIV, fig. 11). 
MystipEs ELONGATA, Southern, 1914. Plate XX XV, figs. 1 and 1la—bristles. 
Specific Characters.—Head twice as long as broad ; eyes two in postero-lateral angles, 
no lenses; four long, slender tentacles in front. Body slender, elongate (6 mm.), and has 
eighty segments, colour yellowish or dark green. First segment has a single pair of long, 
tapering cirri; the second has two pairs. No trace of bristles or spines on the second seg- 
ment. Third segment with a setigerous lobe with bristles and a ventral cirrus. Foot has 
a bluntly pointed setigerous lobe, with a spine and four bristles ; dorsal cirri small and fusi- 
form; ventral cirri longer, slightly enlarged in the proximal half and attached near the 
middle of the setigerous lobe, but posteriorly mereasing in length and moving toward the 
tip of the lobe. In each foot three of the bristles are compound, the shaft being thick, curved 
and bevelled, as well as bifid, but not swollen at the tip ; terminal piece short, wide at the 
base, tapering to a fine point, and with coarse striations. The second bristle is thinner, 
and terminates in a flattened, coarsely striated expansion—with a fine point—which Southern 
thinks is a fused terminal piece, the fusion being most complete posteriorly. Muscular 
stomach in segments 11—13. Mature female has bluish-green eggs, commencing in the 
twenty-ninth seement. 
SYNONYMS. 
1914. Mystides (Mesomystides) elongata, Southern. Proc. Roy. Irish Acad., vol. xxxi, No. 47, p. 74, 
Tolle WW 1eye% LZ 
1921. . elongata, McIntosh. Ann. Nat. Hist., ser. 9, vol. vim, p. 298. 
