62 sr URGES. [VOL. i 



and is often obscured by granules, is bounded internally with 

 more or less distinctness by the subcuticular cells. The term 

 subcuticula has been used interchangeably for the structures 

 here called limiting membrane and intermuscular reticulum ; 

 thus Leuckart, 3 Braun, 8 ( a) Monticelli, 6 E. Walter, 6 and Stafford 9 

 describe the limiting membrane as subcuticula, while Brandes, 4 

 Looss, 1(a) and Braun 8 < b) describe as subcuticula the intermuscular 

 reticulum. This fact together with the appearance of the sub- 

 cuticula in D. patellare suggest that the limiting membrane is 

 differentiated from the intermuscular reticulum, and that in some 

 forms it may be noticeably developed, and not at all or only 

 slightly in others. From the thickness and general appearance 

 of the subcuticula it seems probable that it was once composed 

 of cells, though no trace of these exists in the adult D. patellare. 

 There is hardly a point in the histology of Trematodes which 

 needs study more than that of the subcuticular cells. The 

 existence of a subcuticular cell layer, non-glandular, yet differ- 

 ing in appearance from the rest of the parenchyma, is main- 

 tained by Leuckart, 3 Ziegler, 10 Mace, 11 Looss, 1(a)(b) E. Walter, 6 

 Schuberg, 12 and Goto 13 in Monogenea ; the subcuticular cells 

 are described as glandular by Brandes, 4 Monticelli, 5 Blumberg, 14 

 Poirier, 7 and Katheriner, 15 Brandes asserting and Monticelli 

 denying that they form a continuous layer; while Saint-Remy 16 

 denies the existence of any differentiated subcuticular cells in 

 some forms. 



8 BRAUN, M.: Bronn's Klassen und Ordnungen des Thievreichs, Bd. Vermes. 

 Trematoda. (a) Digenea. (1)) Monogenea. 



9 STAFFORD, J.: Anatomical Structure of Aspidogaster conchicola, Zoo/. 

 Jahrbitcher, Bd. ix, Heft 3, 1896. 



10 ZIEGLER, H. E.: Bucephalus und Gasterostomum, Zeit. f. wiss. Zool., Bd. 

 xxxix, 1883. 



11 MACE, E.: Recherches anatomique sur la grande Douve du foie, Paris, 1881. 



12 SCHUBERG, A.: Zur Histologie der Trematoden, Arbeit, a. d. zool.-zoot. 

 Just. IViirzburgs, Bd. x, 1895. 



13 GOTO, S.: Ectoparasitic Trematodes of Japan, Journ. of Coll. of Science, 

 Imp. Univ. of Japan, 1894. 



14 BLUMBERG, C.: Ueber den Bau des Amphistoma conicum, Inaugural-disser- 

 tation, Dorpat, 1871. 



15 KATHERINER : Die Gattung Gyrodactylus, v. Nrdm, Arbeit, a. d. zool.-zoot. 

 hist. Wiirzburgs, Bd. x, 1895. 



16 SAINT-REMY, G.: Materiaux pour I'anatomie des Monocotylides, Revue 

 biologique du Nord d. I. France, Ann. v, 1892. 



