6 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 123 



in burrows or wandering over land on humid evenings. In all of our 

 collections no specimen has been collected from a stream, pond, or 

 puddle, and most were found at night either wandering above ground 

 or were taken from the mouths of their burrows. A few were dug 

 from their branching burrows. 



In the smaller creeks, C. b. bartonii, C. I. longulus, and C. acuminatus 

 all burrow in the stream beds during the winter months as they do if 

 the water level in the streams becomes low at other seasons. Seldom 

 does C. b. bartonii seem to be content simply to crawl beneath a rock 

 unless it is a rather large one. Even then evidence of excavation may 

 be seen. Cambarus sciotensis, C. acuminatus, and 0. juvenilis appar- 

 ently exert far less effort in digging than do G. b. bartonii and C. I. 

 longulus, but neither of the latter is so typically associated with 

 burrows as is C. carolinus. 



The ostracods. — With only one exception (Uncinocythere biscuspide 

 on a freshwater crab of the genus Pseudothelphusa in Mexico: Hobbs 

 and Villalobos, 1958, p. 395), ostracods of the subfamily Entocytheri- 

 nae seem to be confined to the exoskeleton of craj^fishes. Marshall 

 (1903) reported Entocythere cambaria from the gill chamber of a cray- 

 fish collected at Madison, Wise. In 1926, Sars described Cytherites 

 insignipes (the second known member of the subfamily) from three 

 female specimens collected in Canada but had no further data for 

 them. Klie (1931) described E. donnaldsonensis (=Donnaldsoncythere 

 donnaldsonensis) from Donaldson's Cave, Lawrence County, Ind., but 

 did not indicate that it was associated with a crayfish. Rioja (1940a, 

 pp. 593, 594; 1941, pp. 193, 194) indicated that the habitat of E. 

 heterodonta (= Ankylocythere heterodonta) is quite different from that 

 of Marshall's species inasmuch as the animals are found rarely in the 

 branchial chamber; instead, most of them occur on the outer surface, 

 clinging to the setae. Dobbin (1941, p. 185) reported her E. Columbia 

 (= Uncinocythere Columbia) "from crayfish branchiae." Hoff (1942, 

 pp. 63-65) implied that the primary infestation of the ostracods is in 

 the gill chambers of the crayfish, for, in his "Methods," he indicated 

 that "the ostracods will leave the gills of the host if the crayfishes 

 are placed in a vessel containing 95% ethyl alocohol." He did not 

 indicate that he found them elsewhere on the crayfish, but he did state 

 that he found them "in the water of crayfish burrows." Kozloff and 

 Whitman (1954, p. 159) reported that E. Columbia and E. occidentalis 

 (=U. Columbia and U. occidentalis) "occur principally among the 

 cuticular hairs on the ventral side of the thorax of the host, but a few 

 are found among the mouth parts and on the branchiae." Kozloff 

 (1955, p. 156) indicated that E. erichsoni and E. caudata (=£/. 

 erichsoni and U. caudata) that remained on their hosts after preserva- 

 tion "were found primarily among the cuticular hairs on the ventral 



