90 Michael D. Stuart and Grover C. Miller 



skin penetration. Larvae attached initially to the stomach mucosa but 

 migrated posteriorly to the intestine as they matured. Baker felt that 

 late summer and early fall, when marsh size was reduced and frog 

 density was highest, was the most important period for parasite 

 transmission and that O. pipiens could overwinter in its host. Hendrikx 

 (1981) studied the seasonal fluctuation of O. filliformis in Bufo bufo 

 L. in the Netherlands, and he reported L 4 larvae embedded in the 

 stomach mucosa of overwintering hosts. 



Oswaldocruzia specimens were only rarely found outside the stomach 

 in the box turtles of our study. An infective mode involving skin 

 penetration, while feasible in an amphibian, is somewhat more difficult 

 to accept in the heavily armored box turtle. While softer areas of 

 skin are found around the base of the legs and throat, chance nematode 

 access and penetration could scarcely account for the very high levels 

 of infection. The habits and habitats of the extremely wide range of 

 amphibian and reptile hosts of Oswaldocruzia provide additional reasons 

 to suspect an alternate route of infection. Storeria dekayi (Holbrook), 

 S. occipitomaculata (Storer), Anolis carolinensis (Voigt), many ranid 

 and bufonid species, Typholtriton spelaeus Stejneger, and Terrapene 

 Carolina use a broad spectrum of habitats including semi-fossorial, 

 arboreal, aquatic, semi-aquatic, cave-dwelling, and terrestrial. These habitat 

 differences alone would severely hamper transmission of a parasite 

 dependent on skin penetration to infect. Circumstantial evidence based 

 on host diversity and host diet suggests that Oswaldocruzia might use 

 an alternate life cycle with gastropods as intermediate hosts. In support 

 of this contention, we found a small male Oswaldocruzia completely 

 embedded in a piece of snail tissue taken from the stomach of a 

 freshly killed box turtle. While as yet unproven, morphological and 

 biological differences in the parasites and the different hosts suggest 

 that the species of Oswaldocruzia in box turtles is distinct from O. 

 pipiens. 



Spironoura affinis Leidy, 1856 — Leidy (1856) erected the genus 

 Spironoura and listed two species: S. gracile from the stomach of 

 the red-bellied turtle, Pseudemys rubriventris (Le Conte) (=Emys serata) 

 and S. affine, later modified to S. affinis by Yamaguti (1961), from 

 the cecum of the box turtle, Terrapene Carolina {-Cistudo Carolina). 

 Yorke and Maplestone (1926) designated S. gracile as the type species 

 apparently because it appeared first in Leidy's manuscript. This species 

 has not, however, been collected since its description. Freitas and 

 Lent (1942) felt that S. gracile should be considered a species inquirendum 

 since Leidy's description was brief and incomplete. They proposed 

 revalidation of the genus Falcaustra Lane, 1915 with all of the species 

 of Spironoura transferred to this genus. Some authorities (Yamaguti 



