Trematodes of the Northumberland coast. No. II / by Marie V. Lebour.

  • Lebour, Marie Victoria, 1876-1971.
Date:
[1907?]
Catalogue details

Licence: In copyright

Credit: Trematodes of the Northumberland coast. No. II / by Marie V. Lebour. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    A long and narrow oesophagus runs to about half way down the body, and there branches into two short lobes. Between these lobes and slightly in front of their termination is the small ventral sucker, 0-023 across. I'his Spelotrcma does not appear to fit in with any known species. Cercaria balani, nov. (Plate I. fig. 6, 7.) This species occurs encysted in the common barnacle, Balanns halanoides, which encrusts the rocks and mussels at Budle and Fenham Flats. The cyst is thin-walled and spherical, measuring o'04 mm. in diameter. In it is curled up a pale yellow cercaria measuring, when extended, about i mm. in length. Unfortu- nately measurements of the organs were not made and the specimens were preserved badly, so that at present they cannot be determined. The size of this species suggests its being the larval stage of Spelotrema excellens, NicolP which lives in the Herring Gull Lams argentatus, and this would be a very likely host for the worm, as the Herring Gull is one of the common feeders on the coast. It, however, differs froin Spelotrema excellens in the position of the pharynx, which is situated nearer the intestinal lobes than the oral sucker, thus giving great length to the prepharynx. The intestinal lobes extend slightly beyond the ventral sucker. The body is covered with small spines. Cercaria carcini, nov. (Plate L, fig. 8-9). This cercaria occurred encysted in Carcimis mcenas, the common green crab of our coast. When pressed out of the cyst it corresponds in almost every way with the worm from the same crab described by McIntosh|. It is 0-54 mm. long, its smallest breadth being in the centre of the body. The suckers are almost equal. The oesophagus is more than twice the length of the prepharynx, and the intestinal lobes reach to the level of the anterior margin of the ventral sucker. Two round bodies, * NicoU, II'., Op. cit.. Ann. and Mag. Nat. Hist., Ser. 7, Vol. XX., 1907, p. 248. t Slclnlosh, “ The Trematode Larva and Ascaris of the Carcinus mceiias,” Journal of Microscopical Science, Vol. V., N.S., 1865, p. 201. lO