452 SPHASROSYLLIS OVIGERA. 
pieces of the bristles, the structure of the simple bristles and spines, and the well-developed 
buccal segment. It is near Spherosyllis Claparedu, Khlers, but in the latter the buccal 
segment is fused with the head, and no papille occur on the feet or on the anal segment 
(Southern). The bristles are shown im Plate CXXXV, figs. 7 and 7a. 
SPHHROSYLLIS OVIGERA, Langerhans, 1879. Plate CXXXV, fig. 9-—head and anterior region 
(after Langerhans). 
Specific Characters.—-Head with four large eyes, posterior pair nearer each other, anterior 
a little in front. Three tentacles in a transverse line. Median tentacle in a line with or 
in front of the anterior eyes. Body about 1°5 mm. long; segments twenty-four to twenty- 
eight, beset with papille and encrusted with mud. Dorsal cirri with enlarged bases and 
almost pear-shaped. Pharynx with a tooth anteriorly; proventriculus with ten rows of 
dots; two thick anal cirri. Dorsal bristles simple, slightly bent at the tip. Terminal process 
of ventral bristles somewhat long, with curved ends and spikes. End of shaft dilated, with 
a process in front. 
SYNONYMS. 
1879. Spherosyllis ovigera, Langerhans. Zeitschr. f. wiss. Zool., Bd. xxxu, p. 567, Taf. xxxii, fig. 23. 
1915. . es Allen. Journ. M. B. A., vol. x, p. 597. 
1921. », e McIntosh. Ann. Nat. Hist., ser. 9, vol. vin, p. 303. ) 
Habitat.— Dredged in Plymouth Sound, near New Grounds Buoy (Allen). 
Abroad it ranges to Madeira (Langerhans), where it occurs amongst algze between tide- 
marks. 
In this form the head (Plate CXXXYV, fig. 9) has four large eyes, the posterior pair nearer 
each other, the anterior a little in front. The three tentacles are in a transverse line, the 
median often in front of the anterior eyes. The palpi are broad and flattened. The body 
is about 1°5 mm. in length, and the mature form has from twenty-four to twenty-eight 
segments, the surface beg beset with papilla and encrusted with sand and mud—a feature 
which enabled Dr. Allen to separate it from S. hystrix found along with it. The dorsal 
cirri are short. with enlarged bases so as almost to be pear-shaped, and there are two thick 
anal cirri. The pharynx has a tooth anteriorly and the proventriculus has ten rows of dots. 
The dorsal bristles are simple, shghtly curved at the tip. The terminal process of the ventral 
bristles is somewhat long, with a curved end and spikes ; moreover, the end of the shaft is 
dilated, with a process in front. 
Langerhans found two males with swimming-bristles and sperms. A female carried 
egos on segments 12—15, whilst another had on its ventral cirri either ova or embryos. The 
females had no swimming-bristles. He thought that it approached S. pirifera and S. hystria, 
but the great size of the palpi and the shape of the median tentacle are characteristic. 
This species is entered in the list from Plymouth, but some uncertainty exists, though 
it may yet be found on the southern coasts. As mentioned on p. 159 of vol. 1, Part I, of 
the monograph, Dr. Allen’s preparation showed that the structure of the foot, the presence 
of a single slightly curved and pointed bristle and the structure of the compound bristles 
all agree with S. hystrix. The example from Plymouth did not show the spine on the 
enlarged terminal region of the shaft as figured by Langerhans. 
