Trematode Parasites of British Birds. 



217 



fish, which feed Largely on crustaceans, annelids, and each 

 other. From these and other considerations it would appear 

 that, in the littoral zone, at least, where both have a common 

 feediiifii-ground, birds derive their Distomid parasites from 

 nioUiisks *, while fish obtain theirs from crustaceans, 

 annelids, and each other. This seems to afford an explana- 

 tion of the absence of Distomids in the three above-cited 

 cases. 



For ease of reference I subjoin 

 their respective parasites : — 



Alca torda, Linn. Razorbill. 



Tocotrema linfjua (CVe/j/.). 

 ? Spelotrema simile, Jcif/ersk. (juven.). 

 Lants arymtatus, Briinn. Herriuj.'--(.Jull. 



Gymnopliallu3 deliciosus (Olsson). 



^faritrenia lepidum, sp. n. 



Parorchis acanthus, Nicoll. 



Spelotrema excellens, sp. n. 



( = Sp. simile, Jiiyersk., Nicoll.) 



Tocotrema lingua ( Crept.). 



Monostomum sp. (juven.). 

 Larus catws, Linn. Common Gull. 



Parorchis acanthus, Nicoll. 

 Larus ridibundus, Linn. Black-headed Gull. 



Maritrema <ri-atiosum, sp. n. 

 rhalacrocorax graculus (Meyer). Shag. 

 ? Cryptocotyle concavum {Creijl.). 



Oidemia nigra (Linn.). Scoter. 



Gymnophallus dapsilis, sp. n. 



Psilostomum brevicoUe (Crept.). 



Spelotrema pyofmajum (Levins.). 

 Oidemia fuscn (Linn.). Velvet Scoter. 



Gymnophallus dapsilis, sp. n. 



Psilostomum brevicolle (Crej/l.). 

 Spelotrema pygmasum (^Leviyis.). 



a list of hosts with 



Intestine. 

 Intestine. 



Gall-bladder. 



Intestine. 



Bursa Fabricii, rectum, 



and intestine. 

 Intestine and caeca. 



Intestine. 

 Intestine. 



Eectum. 



Intestine. 



Intestine, 

 rectum. 



ca?ca, and 



Mouostouium .sp. 

 Pelidna (Trinya) atpinn (Linn.). Dunlii 

 Maritrema gratiosum, sp. n. 

 Spelotrema feriatum, sp. n. 



Spelotrema claviforme (Brdi.). 



Totanus catidris, Bech.st. Redshank. 

 Maritrema humile, sp. n. 



Bursa Fabricii. 



Intestine. 



Intestine. 



Bursa Fabricii 



? cpecaj. 

 Intestine, cjeca, 



rectum. 

 Intestine, 



rectum. 

 Creca. 



(and 



and 



c&ca, and 



Intestine. 

 Intestine, 



rectum. 

 Intestine, 



rectum. 



Intestine. 



ca;ca, 



and 

 and 



* An im^ 

 which are obtai 



portant exception to this is the case of some Spelotrema species, 

 obtained, partly at least, from Cancer payurus and Carvinus 



