128 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 83 



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side in two specimens, on right in one (pi. 6, fig. 2). Uterus forms 

 metraterm at level of ventral sucker, the two parts separated by a 

 w^ell-developed sphincter (pi. 6, fig. 3). Metraterm pursues fairly 

 straight course to sinus on ventral surface of body, then bends ven- 

 trally and joins prostatic part of vas deferens to form thick-walled 

 hermaphroditic duct. Prostatic part of vas deferens saclike, con- 

 stricted into two portions and connected with large trilobed seminal 

 vesicle by narrow duct surrounded by numerous prostate cells. Eggs 

 IC/^ by 12(1. 



Host. — TrlcMurus lej>tums. 



L cation . — S t o m a ch . 



Locality. — Galveston Bay, Tex. 



Type specivie7i. — U.S.N.M. Helm. Coll. no. 39518; paratype, no 

 39521. 



Reviarl's. — Only one other species of this genus as restricted by 

 Looss (1907) has hitherto been described from American lislies with 

 suflicient accuracy to be specifically recognizable, namely, L. synodi 

 JNIanter (1931), although some of the forms referred by Linton 

 (1898, 1901, 1905) to Dlstomum monticellH may be species of Lecl- 

 thochirium and may even be identical with the form here described. 

 L. microstoimim differs from L. synodi in the greater relative differ- 

 ence in size of the suckers, in the presence of a bladder in the pro- 

 static part of the vas deferens just behind the hermaphroditic duct, 

 and in the larger size of the eggs. These flukes were found in small 

 numbers in two out of three specimens of Trichiurus lepturus. 



unidentified distome 



Plate G, Figure 4 



A few specimens of an unidentified distome, which may be iden- 

 tical with Linton's '■^Dlstomum sp. from Memdla notata " (1901, pi. 

 32, figs. 357, 358), were found in Menidia menidia along with Rhipi- 

 docotyle transversale. The specimens were extremely fragile, with 

 a tendency to stick to glass during the process of preparation, and 

 were so densely crowded with eggs that no organs except the suckers 

 and pharynx could be identified. The flukes are about 0.48 to 0.7 

 mm long, with greatest transverse measurement from dorsal to ven- 

 tral side through ventral sucker. Ventral sucker in large specimen 

 (0.7 mm long) 140/^'., oral sucker 70/a, i)harynx 50/i. Eggs about 22/a 

 by 12/.. 



