55 



finely, tlir vulva occupying the same relative ]x>sition and 

 presenting the same prominent appearance U. described by 

 this author. The tail of the male was unfortunately not 

 studied in its details at the time, and the unused males were 

 lost by a student to whom they were entrusted for histo- 

 logical study; but the general features of shape and size as 

 well as the appearance and size of the spicule were noted, 

 lateral calcareous bands, as described by Dujardin, were 

 constant in the specimens, and, too, scattered granules in the 

 walls of the alimentary and genital tubes. Believing witli 

 Sclineidertlial there is doubt as to the correctness of Dujardin's 

 description of the mouth, we regard this material as 

 identical with the oxyuris of the writers quoted. 



Some months later (1906) Dr. Fox, the present pathologist 

 to the Zoological Gardens, obtained at autopsy from the large 

 intestine of another species of iguana (Cyclura nubila) numer- 

 ous specimens of a smaller nematode, which on superficial 

 examination was believed to be Oxyuris megatyphlon; but 

 subsequent study has shown differences of structure constant 

 and sufficient in character in our view to require reference 

 of our specimens to a new but closely allied species, for which 

 we propose the name Oxyuris microtyphlon. The notes of 

 study, made October 30, 1906, follow: "Several hundred 

 specimens of a small nematode worm obtained from the 

 cecum of an iguana which had died in the Philadelphia 

 Zoological Gardens (P. Z. G. Lab., 827) were submitted for 

 identification, a very large proportion being quite small and 

 undeveloped, the majority of the developed examples being 

 non-gravid females. Of the developed specimens, the largest, 

 females, measure 5 to 6 mm., or slightly more, in length, the 

 males attaining a maximum length of 4.5 mm. The worms in 

 transverse section are round ; viewed in length are delicately 

 fusiform, tapering anteriorly from the thickest part near the 

 middle (0.3 to 0.5 mm.) to a rounded head which measures 

 roughly between 0.05 and 0.1 mm. in diameter. Posteriorly 

 the females (Figs. 5 and 6) taper gradually to the anus, where 



