Systematics of Troglobitic Caecidotea 69 



15; Hawkins River, 2 Aug 1980, J. Oberlies, 5$$, 999; Roaring River, 

 Shrimp Pools area, 19 Aug 1980, J. Lewis, T. Lewis, 1$$, 1499; pools 

 in Carlo's Way, 17 Oct 1981, J. Lewis, T. Lewis, M. Hale, 4$$, 399; 

 same location, 28 Dec 1981, J. Lewis, T. Lewis, J. Eckstein, 1$, 19- 

 Parker Cave, Parker River, 20 Aug 1980, J. Lewis, T. Lewis, 8<$<$, 

 1599. Barren Co., Mill Hole, 20 Aug 1980, J. Lewis, T. Lewis, 1$$, 

 1499. Simpson Co., Old Smokey Cave, 20 mi. SW Bowling Green, 1 

 July 1981, J.R. Holsinger, 2\$$, 1999. 



Diagnosis. — Caecidotea b. whitei can be distinguished from the 

 nominate subspecies by the straight lateral process of the male second 

 pleopod endopod tip of C. b. whitei, which is placed directly on the 

 margin of the endopod. In mature males where both the medial and 

 distal processes are well developed, the medial process usually appears 

 as a large triangular process with a shoulder distally, rather than a well 

 developed bicuspate process. This characteristic, however, is also shared 

 with some populations of C. b. bicrenata. 



Range. — Caecidotea b. whitei occurs from northcentral Tennessee 

 north to Hart County, Kentucky, where the faulted, sandstone Hart 

 County Ridge is apparently a barrier to its dispersal. To the west the 

 species occurs across the Pennyroyal Plateau, from Mammoth Cave 

 into western Kentucky, and the extension of the plateau in southern 

 Illinois. Caecidotea b. whitei appears to exclude C stygia in the Penny- 

 royal west of Mammoth Cave. In the Kentucky and Illinois counties 

 adjacent to the Ohio River, C stygia again occurs, and at least in Har- 

 din County, Illinois, C. b. whitei is absent. In southwestern Illinois, C. 

 b. whitei again replaces C. stygia, although C stygia is reported from 

 western Illinois and eastern Missouri (Fleming 1972a, b; Lewis and 

 Bowman 1981; Peck and Lewis 1978). In the Mammoth Cave System of 

 central Kentucky, both species occur syntopically, with C. stygia in 

 small streams in the upper levels of the cave and C. whitei in the base 

 level cave rivers (Lewis and Lewis 1980; Lewis 1981a) 



Discussion. — In support of the synonymy of Caecidotea meisterae 

 with C. whitei, illustrations of the gnathopods of both forms from a 

 habitat in Mammoth Cave are given in Figure 2. Figure 3 illustrates the 

 tip elements of male second pleopod endopods. Figure 4 illustrates male 

 pleopod 1, and Figure 5 shows the palmar margin of the propodus of 

 male first pereopods. Although C. meisterae is the more differentiated 

 of the two forms, C. whitei is chosen as the senior synonym for two 

 reasons. First, in the numerous collections examined both here and in 

 Lewis and Bowman (1981), the morphology of C. whitei is by far the 

 more prevalent and typical of the species. Second, the type-locality of C. 

 whitei, Cricket Cave, is a well known but remote locality that is cur- 

 rently unthreatened by man. In contrast, the type-locality of C. meiste- 

 rae in Johnson County, Illinois, lies adjacent to an active limestone 

 quarry. Although still some distance from the cave, this quarry has 

 already consumed one cave (Bretz and Harris 1961), and local residents 

 believe that the quarry operations may eventually consume other sec- 

 tions of White Hill. 



