A NEW CESTODE, OPHIOTAENIA CRYPTOBRANCHI NOV. SPEC, 

 FROM CRYPTOBRANCHUS ALLEGHENIENSIS 



(DAUDIN).* 



GEORGE R. LA RUE, UNIVERSITY OF MICHIGAN. 



Up to the present time but two species of Ophiotaenia, 0. lonnbergii 

 (Fuhrmann) and 0. filaroides La Rue are known from tiie amphibia of North 

 America. The species about to be described under the name Ophiotaenia 

 cryptohranchi nov. spec, adds the third to the Hst. The specific name is de- 

 rived from the name of the host inhabited by this form. 



Diagnosis. Length, as much as 30 cm. Maximum width, about 2 mm. 

 Head, globose, 0.342 mm. broad, 0.324 mm. long. Suckers, four, 0.18 mm. 

 long by 0.11 mm. broad. Neck, 3.2 mm. long. Youngest proglottids, 

 much broader than long. Nearly mature proglottids, 0.4-0.77 mm. long 

 by 1.44-1.36 mm. broad. Ripe proglottids, 1.16-2.68 mm. long by 1.94- 

 1.32 mm. broad. Genital pore, marginal, irregularly alternating, situate 

 at end of first ninth, eighth, sixth, or fourth of proglottid length. Cirrus- 

 pouch, about 0.31 by 0.088 mm. in nearly mature proglottids, 0.335 by 

 0.124 mm. (cirrus unprotruded) in ripe proglottids, reaching 1/6-1/4 across 

 breadth of the proglottid. Protruded cirrus, slender, long. Cirrus and 

 ductus ejaculatorius form 4 or 5 coils in cirrus-pouch. Testes, 107-160, in 

 two fields. Vagina, usually posterior to cirrus-pouch, sinuous in mid-field 

 of proglottid. No sphincter vaginae. Uterus, with 15-20 lateral pouches 

 on either side. Eggs, spheroidal, yolk mass about 0.02 mm. in diameter. 



Material. The description is based on a single worm taken. May 21, 

 1913, from the small intestine of Cryptobranchus allegheniensis (Daudin) 

 (type host) purchased for laboratory purposes at Meadville, Pa. (type 

 locality). The material consisted of five pieces of which the piece with the 

 head measured 14.5 cm. A piece made up of ripe proglottids was 10 cm. 

 long and there were 3 pieces each about 1.5 cm. long containing mature 

 or nearly ripe proglottids. Since only one head and anterior region was 

 found it is assumed that all these pieces belong to one specimen. The 

 type specimen (microscopic slides and alcoholics) bear the serial number 

 391 in the collection of the author. 



EXTERNAL CHARACTERS 



The length of the entire animal after preservation is 30 cm. In width 

 the strobila varies considerably. A minimum width of 0.23 mm. occurs at 

 a point 1.26 mm. posterior to the tip of the head. From this point follows 

 a gradual increase in width to the end of the fifth cm. where the width is 

 about 1.5 mm. From this point to the 13th cm. the increase in width is 

 more gradual than before. At the 13th cm. the width is about 2 mm. There- 

 after the width decreases irregularly. The 10 cm. piece, noted in the state- 



* studies from the Zoological Laboratory, The University of Michigan, No. 142. 



