A NEW TREMATODE (STYPHLODORA BASCANIENSIS) 

 WITH A BLIND LAURER'S CANAL. 



By Joseph Goldberger, 



Passed Assistant Surgeon, U. S. Public Health and Marine- Hospital Service. 



While studying; the helminthological collections in the U. S. 

 National Museum, I found three toto mounts, one series of frontal 

 sections, and six specimens in glycerine- alcohol all of one species of a 

 trematode from the liver of a Bascanion constrictor collected by Dr. 

 Albert Hassall near Alexandria, Virginia, on July 13, 1892. One of 

 the toto mounts was presented to Prof. Ch. Wardell Stiles by Doctor 

 Hassall, while the remaining specimens form a part of the Hassall 

 collection. 



For the privilege of studying this material I am indebted to both 

 Doctor Hassall and Professor Stiles. 



EXTERNAL CHARACTERS. 



Size. — The specimens in alcohol vary in length from 3.8 to 4.88 

 mm. and in width from 1.72 to 2.92 mm.; the three mounted speci- 

 mens vary from 3.7 to 5 mm. in maximum length and from 2 to 3 mm. 

 in maximum width. 



Color. — The worms in alcohol are of an olive green tint with a dark 

 area corresponding to the egg-distended uterine coils. 



Form. — -The body is dorso-ventrally flattened; in ventral view it is 

 oval in outline with a somewhat attenuated, bluntly pointed oral end 

 and a bluntly rounded caudal margin. A transverse section near the 

 cephalic end is subcircular in outline; farther caudad transverse 

 sections are elliptical with relatively very short dorso-ventral diam- 

 eter. Thus, a transverse section in the testicular zone of one 

 specimen measures 1.42 mm. in transverse diameter and 0.375 mm. 

 in dorso-ventral diameter. 



Surface. — The surface cuticle is thin, measuring about 4 /< in thick- 

 ness and is armed with delicate spines. The spines are not very 

 numerous and do not appear to be uniformly distributed, being very 



Proceedings U. S. National Museum, Vol. 40— No. 1 81 7. 



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