434 
Marine Cercariae 
Cercaria carcini mihi (1908 a, p. 10). 
(PL XXVI, figs. 13, 14.) 
This was found encysted in Gmxinus maenas from Fenham Flats. 
Only a few specimens were examined but in no case were the cercariae 
frequent. The cyst is oval and thin-walled, 0'40 x 0'3.5 mm. The 
cercaria when pressed out of the cyst measures 0'.54 mm. in length, 
suckers almost equal, intestinal lobes reaching to the level of the 
anterior margin of the ventral sucker. Body covered with spines except 
at the posterior end. This is very like S. excellens but I think from the 
character of the cyst that it is a different species. 
Cercaria minor sp. inq. 
(PI. XXVII, figs. 1, 2.) 
Occurs in smaller cysts than 8. excellens but with them in Garcinus 
maenas. The cyst wall is much thinner. Breadth of cyst 0‘26 mm. 
The cercaria contained within it is well developed and certainly distinct 
from 8. excellens. Length 0'.52 mm. Body covered with spines except 
at the posterior end. Oral sucker 0‘46 x 0'40 mm., broader transversely. 
Ventral sucker 0'40 mm. Prepharynx and oesophagus long. Intestinal 
caeca reaching to just beyond the posterior border of the ventral sucker. 
Genital pore to left of ventral suckei’. Testes and vitellaria behind. 
The further life-history is not known. 
Cercaria corophii mihi (1908 a, p. 9). 
(PI. XXV, figs. 18, 19.) 
This cercaria occurs frequently encysted near the surface of the body 
and legs of the amphipods Goropldum grossipes and Gammarus duebeni 
especially in the former, just beneath the cuticle. All those found were 
from Fenham Flats. The cyst is slightly oval 0T6 x 0T4 mm., with 
thick transparent walls. When pressed out of the cyst the cercaria 
measures 0 34 mm. in length, broad at the base with head end tapering. 
Body covered with spines except at the posterior end. Oral sucker 
0 03 mm. across, narrow prepharynx 0’04 mm. long, pharynx O'Olfi mm., 
long oesophagus branching into caeca reachiug just beyond the posterior 
border of the ventral sucker. Ventral sucker 0 023 mm. across. 
Nothing further of the life-history is known. 
