58 CATALOGUE OF ENTOZOA. 
23. DistoMa MicRocEPHALUM, Baird. (Tab. II. f, 2.) 
Body of an elongated oval or lanceolate shape, of a slightly yel- 
lowish-white colour, plicated transversely, the folds being very 
fine; head narrow, obtuse, separated from the body by a con- 
traction; posterior extremity obtusely lanceolate; dorsal sur- 
. face slightly convex ; ventral surface nearly flat, or somewhat 
concave; anterior sucker small, terminal; ventral sucker 
larger, round, prominent, and surrounded by an elevated, 
thickened edge, and situated within 3 millimetres of the 
former; organs of generation placed halfway between the two 
suckers, and in form of an elevated papilla. 
Length from 6 to 8 lines, greatest breadth 14 line, 
Hab. Stomach of the Spinous Shark, Acanthias vulgaris. From 
Falmouth Harbour. 
From the collection of W. P. Cocks, Esq. 
24. DIsToMA ISOSTOMUM. 
Distoma isostomum, Rudolphi, Synopsis Entoz. 105 & 392, n. 62; 
Creplin, Nov. Obs. de Entoz. 64; Baer, Nov. Act. Acad. Ces. Nat. 
Cur. xiii. 553; Dujardin, Hist. Nat. Helminth. 471; Diesing, 
Syst. Helminth, i. 363. 
_ Hab. Ganglions in the common Cray-fish, Potamobius astacus. 
From the collection of M. Siebold. 
25. DISTOMA CIRRIGERUM. 
Distoma cirrigerum, Baer, Nov. Act. Acad. Nat. Cur. xiii. 553; 
Dujardin, Hist. Nat. Helminth. 472. 
Distoma isostomum? Diesing, Syst. Helminth. i. 363. 
Hab. Hydatid tumours of the common Cray-fish, Potamobius 
astacus. 
From the collection of M. Siebold. 
26. DistomMA HOLOSTOMUM. 
Distoma holostomum, Rudolphi, Syncpsis Entoz. 94 & 368, n. 12; 
Dujardin, Hist. Nat. Helminth. 446; Diesing, Syst. Helnvinth. 1. 
339. 
Hab. Intestines of the Spotted Crake, Ortygometra porzana. 
From the collection of M. Siebold. 
