Studies on microphallid trematodes from China. 1. Genus Maritrema, including descriptions of four new species.

Eight species of microphallid trematodes belonging to the genus Maritrema are reported in this paper.Of these,4 are new to science and 4 are new records for this country.(1) M.majeatova sp.nov.(figs.1,2) Body flat,pear or tongue-shaped,0.407-0.566 by 0.277-0.347 (average 0.480 by 0.322) mm.Oral sucker terminal,0.029-0.037 by 0.029-0.037 (0.032 by 0.033) mm.Acetabulum 0.029-0.040 by 0.029-0.040 (0.033 by 0.033) mm,located on midbody or slightly forward.Prepharynx short.Pharynx 0.015-0.026 by 0.015-0.022 (0.020 by 0.018) mm.Oesophagus 0.022-0.073 (0.048) mm long.Caeca extending to posterior level of acetabulum,Testes oval,symmetrical and located behind acetabulum and ovary.Left testis 0.055-0.073 by 0.099-0.120 (0.063 by 0.110) mm,right testis 0.048-0.073 by 0.091-0.120 (0.061 by 0.107) mm,Cirrus pouch 0.029-0.037 by 0.063-0.102 (0.034 by 0.071) mm,containing seminal vesicle,prostatic glands and ejaculatory duct.Genital pore opening to the left of acetabulum.Male papilla indistinct.Ovary oval or slightly lobed,0.022-0.037 by 0.056-0.073 (0.031 by 0.066) mm,transversally located to the right of acetabulum.Uterus occupies the entire space behind acetabulum.Vitellaria horseshoe in shape,occupying posterior half of body,sometimes interrupted anteriorly or posteriorly.Eggs 22-27μby 18-22 (25 by 20)μ,with vary thick shell 1.8-2.9 (2.3)μHost:Charadrius alexandrinus dealbatus(Swinhoe).Location in host:Intestine.Locality:Zhanjiang,Guangdong,China.M.majestova may be distinguished from the other species of the genus by the following:eggs large,with very thick shells of 1.8-2.9μ;ovary located to the right of acetabulum;oral sucker and aeetabulum nearly equal in size;male papilla indistinct.(2) M.macropharynga,sp.nov.(fig.3) body flat,pear-shaped,0.220-0.336 by 0.214-0.322 (0.294 by 0.254) mm.Oral sucker terminal,0.026-0.052 by 0.029-0.063 (0.041 by 0.046) mm.Acetabulum 0.040-0.048 by 0.040-0.059 (0.045 by 0.047) mm,situated on mid-body.Pharynx muscular and large,measuring 0.029-0.055 by 0.029-0.052 (0.044 by 0.040) mm.Prepharynx and oesophagus very short.Caeca extending to the level behind posterior border of acetabulum.Testes oval,behind acetabulum.Left testis 0.022-0.055 by 0.048-0.088 (0.037 by 0.064) mm,right testis 0.022-0.055 by 0.037-0.088 (0.037 by 0.060) mm.Cirrus pouch 0.018-0.037 by 0.110-0.148 (0.032 by 0.123) mm in size.There is a protrusile male papilia provided with hooks.Ovary measuring 0.018-0.037 by 0.052-0.084 (0.026 by 0.073) mm;with irregular margin,located dorsally to acetabulum and just behind cirrus pouch.Seminal receptacle present.Vitellaria in posterior half of body,horse-shoe in shape,interrupted posteriorly.Uterus occpies posterior half of body.Eggs 15-18μ by 8-11μ.Host:Charadrius dominious fulvus Gmelin.Location in host:Intestine.Locality:Beihai,Guangxi,China.M.macropharynga is distinguishable from the other species of the genus by a large pharynx,nearly as large as the oral sucker and acetabulum,a protrusile male papilla provided with hooks;short prepharynx and oesophagus.M.macropharynga is somewhat similar to M.macravestibulum Ogata,1951,but in the latter the body and organs are larger,the male papilla is absent,the prepharynx and oesophagus are longer and the Vitellaria are interrupted anteriorly.(3) M.papillorobusta,sp.nov.(fig.4) Body pear-shaped,0.410-0.560 by 0.325-0.436 (0.500 by 0.405) mm.Oral sucker terminal,0.042-0.055 by 0.040-0.048 (0.046 by 0.044) mm.Acetabulum 0.055-0.073 by 0.055-0.073 (0.064 by 0.065) mm,located near midbody.Prepharynx short.Pharynx 0.033-0.040 by 0.026-0.040 (0.037 by 0.032) mm.Oesophagus 0.059-0.080 (0.065) mm in lengh.Caeca extending to level of acetabulum.Testes spherical or transversally elliptical,symmetrically located in posterior fourth of body.Left testis 0.029-0.059 by 0.088-0.120 (0.042 by 0.103) mm,right testis 0.029-0.066 by 0.84-0.125 (0.046 by 0.103) mm.Cirrus pouch 0.052-0.066 by 0.177-0.266 (0.060 by 0.207) mm,a large protruded male papilla,measuring 0.052-0.070 by 0.170-0.214 (0.056 by 0.180) mm,and covered with spines of varying size.The papilla ex