Dalhousie Springs hydrobiids zc 
Cd) very long, straight. Sperm sac globular, 0.34-0.46 mm in maximum length, 0.17-0.39 mm in 
maximum width. Albumen gland (Fig. 14A) 0.96-1.23 mm in length, 1/10—1/7 of length in pallial 
roof; slightly shorter than capsule gland. Capsule gland rounded anteriorly, oval in section, 1.16- 
39 mm in length, with indistinct glandular zones. Ventral channel narrow, lacking distinct 
Vestibule, small, short opening slightly behind anterior end of capsule gland. 
Distribution (Fig. 15). Common in main pool and outflow of Spring Cal. Springs confirmed as 
containing this species are listed in Table 7 (Appendix 3) and include only members of the A, B, Ca, 
Cb, Cc, and Cd groups. 
This species mostly lives in large warm pools or warm outflows from large springs ranging from 
33-42*C (the majority 35-40*C). 
Remarks. Data from allozyme electrophoresis presented below show, when using the criterion of 
Sympatry, that there is no justification for recognising more than two species-group taxa within 
alhousia. Both are very variable in shell morphology, although D. globosa is generally larger and 
Wider than the species described below. There are no known anatomical characters that can be 
Consistently used to separate these two taxa. The allozyme differences summarized in the diagnosis 
are detailed below. Because of the difficulty in species-level determination and somewhat hazy 
Species boundaries, we have selected specimens for the type series of the two species of Dalhousia 
named here from one of a few populations in which they are known to be sympatric. 
There is a considerable range of variation in shell size and shape (Fig. 3. 16A,C; and Ponder, 
1989, figs 11.1F, 11.2B,C,G) within this species, even within the same spring (Fig. 3A,B, 16C) or 
he same sample (Fig 3C,D). Mean shell length, in the seven measured populations, ranges from 2.5 
to 4.27 mm (Appendix 2, Table 2) with considerable variance in some samples (Appendix 2, Table 
2; Fig, 16A,C), and many populations differ significantly (P<0.001) from conspecific populations in 
length and other dimensions and ratios. Overall there is a difference between sexes in most shell 
dimensions and ratios (Р<0.1). Allozyme variation within this taxon is detailed below (see also 
Appendix 3, Table 7). 
Dalhousia harrisi n. sp. 
Figs 2A-C, Е.С, 4, 5, 7С-Е, 8A,B, 9B-D, 10A,E, ПА, 12B, 13B-D, 14B,D, 15, 16B,D, 17, 22-24. 
Ponder, 1989, figs 11.1A-E,G, 11.2A,D,E. 
Etymology, Named for Colin Harris, as a small recognition of his efforts in the conservation of the 
Mound springs of South Australia. 
Type locality. Cal, the main spring (Earwanyera Spring), Dalhousie Springs, South Australia. 
Collection details of type material. Stn Cal We, Spring Cal, 26°24'29"S 135°31'08"E, fringe of 
10015 on steep edge at water surface on side of main pool. 12/6/1985, Coll. W. Ponder & D. Winn. 
Holotype, SAM, 18939, paratypes, SAM 18940, AMS, С201744. 
Diagnosis, Typically with small to medium, conical to ovate-conic shell. Distinguished 
lectrophoretically from D globosa in having high frequencies of LAP 3, SDH-1 2, SDH-2 1 and 
-1 4 allozymes. 
Description, Shell (Figs 2A-C,F,G, 4, 5). Shell opaque, small (length 2.3-3.8 mm, mean 2.8 mm, 
lin type series), ovate-conic to сопіс, SW/SL 0.64-0.80 (mean 0.71), AL/SL 0.47-0.57 (mean 
0.51), Suture impressed, whorls convex to very slightly shouldered. Protoconch of about 1.5-1.6 
Whorls, minutely punctate. Teleoconch of 2.6-3.6 (mean 3.1) convex whorls, sutures impressed; 
Sculpture of indistinct growth lines only. Aperture slightly longer than wide, AW/AL 0.87-1.01 
Mean 0.94, 0.91 in type series) and angled posteriorly. Peristome entire,with sharp edge, weakly 
thickened internally, with inner lip attached to, or slightly separated from, parietal wall. Colour 
