170 



PROCEEDINGS OF THE NATIONAL MUSEUM. 



VOL. 50. 



and terminates in a short, fine transparent point. The anus is 400 [i 

 from the tip of the taiL 



Hosts. — Apodemus sylvaticus {Mus sylvaticus) , Glis glis {Myoxus 

 glis)^ Dyromys nitedida {Myoxus nitedula, Myoxus dry as) .^ Muscar- 

 dinus avellanarius {Myoxus avellanarius, Myoxus muscardinus) . 

 Location. — Small intestine. 

 Localities. — German}^, France, Austria. 



In a paper already cited (Hall, 1913) I have 

 given the evidence indicating that R'wtularia cris- 

 tata conforms to the generic diagnosis in the pos- 

 session of two rows of cuticular combs, instead of 

 one row as given by Froelich and Dujardin. In 

 the same paper I have noted that in species of 

 Rictularia from rodents, contrary to the rule for 

 species of this genus from carnivores, there is an 

 abrupt transition from the elongate combs in the 

 prevulvar region to the narrow spines in the post- 

 ^* vulvar region. In view of this fact, and of the 

 expression by Dujardin of the fact that the combs 

 tliemselves are not very prominent, it seems reason- 

 ably safe to assert that spines, although not so far 

 described from the post-vulvar region, will be 

 found present on adequate study. 



I have noted above the wide range of measure- 

 ments given by Dujardin for the length of this 

 worm. Further study might show the presence of 

 more than one species in so many host species 

 and necessitate the designation of the typical Ric- 

 tularia cristata. 



RICTULARIA ELVIRAE Parona, i£ 



Fig. 217.— Rictul.\ria 

 CRISTATA. Female. 

 a, Two-TinRDs nat- 

 ural size; h, en- 

 larged. After 

 FROEUCn, 1S02. 



Specific diagnosis. — Rictularia (p. 168) : 

 Male unknown. 



Female 39 to 47 mm. long and 1.25 mm. thick. 

 Two lateral alae are present in the cervical region. 

 These are lobulatc and each bears a cervical papilla 

 a few millimeters posterior of the head (fig. 218). 

 On the anterior surface of the head are two short papillae 45 ^ in 

 diameter. The mouth aperture (fig. 219) is provided with three 

 projections on its dorsal border and three corresponding projections 

 on its ventral border. There are two large round papilliform pro- 

 jections, 14 ju, in diameter, on the interior sides of the buccal capsule. 

 The short esophagus is 21 /u thick. The anus is near the tail. The 



