Dr. Murai Éva szerk.: Parasitologia Hungarica 11. (Budapest, 1978)

An examination of sections in S. minuta and S. scleroporum, deposited in our (Hungarian) collection, seems to indicate that muscular elements of that part are not combined with the anterior sphincter, supporting rather LOOSS'

s (1912) than NASMARK's (1937) opinion (Fig. 1). Although the pharynx of S. minuta shows certain deviations at some points, in our opinion, do not warrant its treatment as a new type of pharynx. Along the oesophagus muscular thickening has not been found, a well developed oesophageal bulb, however, is present (Fig. 3). Its measurement is 320-340 by 480-500

ß and it is composed muscular layers in circular arrangement. The terminal part of the reproductive organ system is fairly simple in its structure, consisting of genital papillae and a small genital atrium, without any circular or radial musculature. The genital papillae are small and slender, the hermaphrodite canal is minute (Figs. 4 and 5). The genital atrium with such a structure should be placed, according to NASMARK's (1937) classification, among the Gracile type. The wall of the genital atrium of S. minuta is more swollen than that of the Gracile type. The cirrus pouch is surrounded by a well developed muscle layer (Fig. 6) and contains a vesicula seminalis interna and a pars prostatica with several prostatic glands (Figs. 4 and 6). From the four groups of acetabulum distinguished by NASMARK (1937) S. minuta' s belongs to "Group I" in which six different types are described. The acetabulum of S. minuta shows resemblance to Cladorchis type, having muscle units of v. e. in a bundle (in case of S. minuta 12- 14) and awell developed obliquely running, longitudinally branched muscle-band (Fig. 9). At the same time it differs from it in having much more muscle units in the dorsal exterior circular layer (about 130-135, Fig. 7). In the latter feature, the acetabulum of S. minuta resembles that of Pseudochiorchis type (TANDON, 1970; SEY, 1973) but differs from it in not having v. e. muscle units in a bundle. Measurements of muscle units in the exterior circular muscle layers vary between 50-100 ju (Fig. 8). Cladorchis type of acetabulum was held by NÄSMARK (1937) for different species, among them Chiorchis fabaceus (Diesing, 1836) as well, indicating 14-58 units in its dorsal exterior muscle layer. Having examined acetabulum of C. fabaceus derived from fresh material (SEY, 1975) it was found, however, that that layer in question consists of two parts; an anterior including about 57-59 muscle units followed by a muscle-unit-free interruption about 350-400

m in length. Behind this interruption, a muscle layer with about 80-85 muscle units is found. These muscle units were not observed by NÂSMARK (1937) in his Cladorchis type. Taking NASMARK' s working theory (acetabulum type generally has generic value) and histo-morphological deviations between the acetabulum of S. minuta and the Cladorchis type into account, it might be considered a new type, the authors, however, hesitate about its designation because the test material available for NÄSMARK was about a century old and it is quite possible that the structural differences above could be due to this circumstance. Therefore we consider the acetabulum of S. minuta of Cladorchis type for the time being. Tieferen ces LOOSS, A. (1912): Über den Bau einiger ausscheinend seltner Trematoden-Arten. - Zool. Jahrb. Suppl. , 15^ 343-361. NÄSMARK, K. E. (1937): A revision of the trematode family Paramphistomidae. - Zool. Bidr. Uppsala, 301-562. Figs. 1-9: Median sagittal sections of Stunkardia minuta 1 = Anterior part of pharynx with pre-sphincter and anterior sphincter; 2 = Posterior part of pharynx with posterior sphincter; 3 = Right half of oesophageal bulb; 4-5 = Genital atria; 6 = Cirrus pouch; 7 = Dorsal half of acetabulum; 8 = Median part of acetabulum with muscle units of dorsal exterior circular muscle layer; 9 = Ventral half of acetabulum with muscle units situated in a bandle and a well developed obliquely running muscle-band.