2 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 9I 



long by 25 to 30 /x wide, isthmus 40 /a long by 20 /a wide, bulb 80 fj. 

 long by 80 to 90 /A wide. Nerve ring 170 fi from anterior extremity. 

 Excretory pore 275 to 320 /t from anterior extremity. Anus 680 to 

 760 fi from posterior extremity ; tail filiform, bearing paired spines. 

 Vulva preequatorial, 320 to 360 /x from anterior extremity, imme- 

 diately posterior to excretory pore. Vagina 790 fi long, directed 

 posteriad, vagina vera 117 /n long, vagina uterina 6/^ [x long; amphi- 

 delphic. Eggs 102 to 104 fi long by 43 to 51 /x wide. 



Host. — Anolis cristatellus. U.S.N.M. no. 9034f. 



Location. — Rectum. 



Type locality. — Pueblo Vie jo, Puerto Rico. 



Type specimens. — U.S.N.M. Helm. Coll. no. 8746; paratypes no. 



8747. 



Parathelandros anolis appears to be closely related to P. mastigunis 

 Baylis, 1930, the only other species of the genus. P. anolis differs 

 from P. mastigurus in the absence of a spicule in the male, the ex- 

 tremely narrow sublateral alae of the female, and the presence of 

 spines on the tail of the female, there being a spicule in the male 

 of P. inastigurus which also has wide lateral alae in the female, and 

 no spines on the tail. 



The affinities of the genus Parathelandros, as evidenced by the 

 study of P. anolis, are worthy of comment. The cephalic papillae 

 being eight in number, separate and distinct from one another, place 

 this genus in the Thelastomatidae rather than with the Oxyuridae, 

 since the cephalic papillae in the Oxyuridae consist of only four 

 papillae which represent complete fusions of the eight papillae of 

 thelastomatids. Since this is the chief distinguishing character be- 

 tween the two families, it appears necessary to remove Parathelandros 

 from the Oxyuridae. 



The alae of P. anolis are particularly interesting, since they show 

 in cross-section characters not generally known. The sublateral alae 

 of the female (pi. i, fig. 5) appear to correspond to the lateral alae 

 of the male (pi. i, fig. 3), the latter probably being formed by the 

 extension and fusion of paired sublateral alae. 



Family SPIRURIDAE 



ASCAROPHIS CESTUS, n. sp. 



Plate I, figs. 7-10 



Cuticle minutely striated except near anterior extremity, becoming 

 wrinkled here and forming a collar (pi. i, fig. 8). Oral opening 



