MANAYUNKIA (HAPLOBRANCHUS) ASSTUARINUS. 305 
distinct. The specimen is considerably smaller than the average size of J. elegans, but is 
most closely allied, and intermediate forms may yet be found. It is mature in May (Southern). 
Langerhans gives a brief account of this species as having the first segment unarmed, 
with large blood-vessels and two oblong red eyes. Collar with only a dorsal median _ shit 
and somewhat higher than in J. elegans. The second segment has a pair of otocysts with 
rounded otoliths and a dorsal tuft of winged bristles. From the third to the ninth segment 
the dorsal bristles are winged. Ventrally the long hooks are narrowed above the shoulder, 
with three teeth above the main fang (Plate CXXXVIII, fig. 5). There are seventeen 
seements in the abdomen with ventral bayonet-shaped bristles, whilst dorsally are avicular 
hooks, the figure being somewhat elongated and the main fang making an acute angle with 
the neck. Southern, again, could find no difference between the bristles (and hooks ?) of 
this form and J. elegans, the presence of a caudal appendage alone distinguishing J. 
caudata. 
Genus CLXXIV.—ManayounkgiA, Jos. Lewdy, 1858 (HAPLoBRANCHUS, A. G. Bourne, 1883). 
Cephalic region consisting of pro- and peristomium almost fused; two prostomial 
tentacles; two palps with a blood-vessel; collar slightly developed. Body minute, 
nearly cylindrical, though slightly tapered posteriorly where the anus opens a little within 
the tip. Two “branchial” stems, each dividing into four simple, free filaments, richly 
ciliated, but devoid of blood-vessels. Tubiparous glands separate. Sexes distinct. 
1, MANAYUNKIA (HAPLOBRANCHUS) ZSTUARINUS, A. G. Bourne, 1886. Plate CXVII, figs. 3 
and 3a—body and anterior region ; Plate CXXXV, figs. 20 and 20a—bristle and hook. 
Specific Characters—Cephalic region as in the genus, the palpi having green blood, 
but the filaments of the branchive are pale. The palps are inferior, the branchie superior. 
Two eyes on the dorsum. Body 4—6 mm. long, nearly cylindrical, but tapered a little 
posteriorly. Anterior region of eight setigerous segments, posterior region of three bristled 
segments. Anterior bristles simple, winged, tapering. Posterior bristles also with wings, 
but the ventral forms have longer tips. Anterior hooks ventral, with broad crowns and 
rather long curved shafts. Posterior hooks dorsal, with larger crowns and straighter 
shafts. In tubes of sandy mud. 
SYNONYMS. 
1883. Haplobranchus xstwarinus, A. G. Bourne. Quart. Journ. Micr. Sci., vol. xxiii, p. 169. 
1910. os 5 Southern. Proc. Roy. Irish Acad., vol. xxviii, p. 242. 
1915. a es Allen. Journ. M. B. A., vol. x, p. 643. 
1916. s 7 McIntosh. Ann. Nat. Hist., ser. 8, vol. xvii, p. 47. 
Habitat.—Coast of Sheppey (Bourne). In mud from the mouth of the Liffey (Bolton). 
Cephalic region furnished with two short prostomial tentacles which have pigment, 
whilst the base is united with the palps, and the peristomial tentacles, which have a continua- 
tion of the body-cavity, and these organs are richly ciliated on their inner faces. The palps 
