ON SOME TREMATODES FROM DARJILING DIST ' RICT , WEST BENGAL , INDIA

During the periods June-July 1974 and May-June 1975, the senior author conducted faunistic surveys of certain areas in Darjiling district (West Bengal) and collected some helminths from vertebrates. The present paper deals with the trematode component of this collection which comprises nine species belonging to nine genera and five families. Of these, one species is new, while others show interesting variations hitherto unrecorded. All meaSurements are in millimeters.

Material.-lex.; Z.S.I. reg.no.W 7260/1; host-Wood peeker (Picusjlavinucha jlavinuclza); location-?; loca1ity~Reang; 7 .vii.1974; ColI.T D. Soota. Descrip.1ion.-Bodyelongated, bluntly rounded anteriorly and gradually tapering posteriorly, 4. 34 X O. 75, with maximum width in testicular zone; cuticle smooth; oral sucker sub .. terminal, 0.23 X 0.27 followed by a small pharynx; oesophagus 0.09 long, bifurcating into intestinal caeca which appear to be somewhat atrophied and run upto the caudal end of the body where their blind ends are obscured; ace .. tabulum 0.45 X 0.49, larger than oral sucker, almost 1:2 in ratio and situated within anterior third of body 0.47 froln anterior end; testes rounded, oblique and just behind acetabulum; right 0.27 X 0.26, left  reangensis sp.n. 0.23 X 0.24; cirrus sac opens to the exterior just below oral sucker; ovary 0.19x 0.14 and 0.38 behind right testis; receptaculum seminis and Mehlis gland' complex present on the postero-late~al side of ovary; vitellaria confined roughly to mid-third of body, asymmetrical in extension extending from behind the posterior testis; uterus extensive with a~cend .. ing and descending loops packed with• eggs, extending posteriorly up to the hinder end of the body and anteriorly up to pharyngeal level running in between testes; eggs yellowish, elliptical, 0.36-0.48X 0.22--0.26.
Remarks.-Yamaguti (1971) on the basis of the position of acetabulum and body shape divided the genus Lypersomum Looss, 1899 into two subgenera viz., Lypersomum and Lypersomoides.The present species on account of its closer proximity of acetabulum and body shape is placed under the subgenus Lypersomum.Yamaguti (1971) included 25 species under it, of which only two viz., L. kavini Fotedar andRaina, 1965 andL. stunkardi Agrawal, 1964 are reported from India.
The present specimen comes close to L. clathratum (Deslongschamps, 1824) in respect of asymmetrical extension of viteIlaria and in size of ova, but differs in body size (being much larger in the present specimen), in ratio of oral sucker and acetabulum and in topography of gonads.
It also comes close to L. kavini Fotedar and Raina, 1965 in position of ovary and in size of ova, but differs greatly in body size, in extension of vitellaria and in ratio of oral sucker and acetabulum.
Further, the present specimen can be distinguished from all other species by smaller body size and in relative size of oral sucker and acetabulum.Hence, the specimen is described as a new species under the name Lypersomulrl (Lypersomum) reangensis n.sp.
Remarks.-This species is cosmopolitan in distribution and shows a lot of intra-specific variations in such characters as body size, position and shape of testes and of ovary, relative size of suckers, extension of vitellaria etc.The present specimens also show variations in lobulation and position of testes which may be symmetrical or obliquely tandem and also in the distribution of vitelline glands.-liver; 21.vi.1974 & 23.v.1975; collector and locality same.
R~marks .-"As this is a common liver fluke, a detailed description is not given.Roy (1954) observed that 50 to 75% of the buffaloes brought to Kalimpong abattoir were infected with this species.The present surveys revealed higher incidence" of infection in buffaloes than in cows in Ghoom.
Remarks.-This species occurs widely in pigs and has also been reported from man.In the present surveys, only two host animals showed infection by this species.Enquiries made at local piggeries revealed that the species is rarely found in the indigenous pigs.
Remarks.-As this is a widely occurring and well described species, a detailed description is not necessary.