88 Transactions.—Z. oology. 
another Isopod (described in the latter part of the paper) whose nearest 
allies are marine. Calliope subterranea is inconclusive, for we have in New 
Zealand one marine and one fresh-water species ; it is, however, not at all 
near to C. fluviatilis the fresh-water species, and certainly has not arisen 
out of that species. 
Gammarus fragilis, again, does not prove anything, for though in New 
Zealand we have only one species, a marine one, in Europe some species 
are marine and some fresh-water. The genus Crangonyx contains only two 
species besides C. compactus, mihi, one C. subterraneus from a well in Eng- 
land, the other C. ermanni from warm springs in Kamschatka ; its nearest 
allied form, however, is a marine genus, Gammarella. 
On the whole, both the Isopoda and the Amphipoda are so distinctly 
marine and their fresh-water representatives in New Zealand so few, in 
fact only two, Calliope fluviatilis and Idotea lacustris, that it is difficult to 
believe that the subterranean fauna, which, so far as at present known, 
contains five species, could have arisen from any other than the marine 
fauna. 
Cruregens fontanus.—8Since writing my previous paper I have obtained a 
great number of specimens of this species—between 40 and 50—and they 
all agree in having the last thoracic segment small and without appendages, 
so that there can no longer be any doubt that the form I have described is 
the adult form. 
In living specimens the heart can be distinctly seen through the trans- 
parent integument. It is elongated and extends from the middle of the 
fifth abdominal segment anteriorly, reaching nearly to the middle of the 
sixth thoracic segment. The anterior end of the heart is narrower than the 
posterior part, and the posterior end is rounded. There appear to be three 
openings through which blood flows into the heart ; one is on the left side 
in the second abdominal segment ; the other two are on the right side, one 
in the seventh (last) thoracic segment, and the other in the third abdominal 
segment. These openings appear to be provided with valves of some kind. 
Blood passes out through the anterior end of the heart, in the median line 
of the body, and flows forwards to supply the various parts of the body. 
In my previous paper I have stated that the only blind Isopoda inhabit- 
ing wells or caves that I could find mention of were two species of a genus, 
Cacidotea, found in the Mammoth Cave of Kentucky and in the Wyandotte 
Cave; since then I have found two others mentioned, but I have not been 
able to get descriptions of them ; they are Titanethes albus, Schiódte, which 
inhabits caves of Carniola* and Typhloniscus steinii.+ 1 
* See “ Nature,” 18th April, 1872, p. 484. 
T See ** Trans. Linn. Soe.," 2nd ser., vol. I., pt. i., p. 24 (footnote). 
Others are mentioned in the Zoological Records for 1879 and 1880. 
