882 The Fauna of the Nickajack Cave. [November, ' 
we are to look for the ancestors of Orconectes hamulatus, On the 
other hand, in the form of the body, of the scale and rostrum, as 
well as of the upper lip and the chelz (though not of the gqno- 
pods), Orconectes hamulatus approaches Cambarus affinis. Now of 
all our North American crawfishes, it would appear, as Mr, Uhler 
has told the writer, and as seems evident to us upon an examina- 
tion of several types and the excellent figures of Dr. Hagen, that 
C. affinis is the more generalized form, and this is tantamount to 
saying that it is the ancestral form of our North American craw- 
fishes. So while our Nickajack blind crawfish may have been an 
immediate derivative of C. Zatimanus of the Gulf States, it probably 
ultimately originated from C. affinis, a more wide-spread species. 
It is also of interest to note that O. hamulatus presents the 
same generic characters as O. pellucidus, the eyes being rudi- 
mentary, functionless, the body long and the appendages slender; 
we thus feel justified in separating the genus from Cambarus. 
Of the two crickets found in Nickajack cave, there were three 
small specimens of Hadenacus subterraneus Scudder, which only 
differed from Mammoth cave individuals in having rather shorter, 
thicker maxillary palpi; but this is not even a varietal difference, 
as the antenne and legs have the same proportions. The other 
cricket is a new species of Ceuthophilus, and may be called Ceu- 
thophilus ensifer Packard.' It is very nearly allied to C. stygus 
of Mammoth cave, but may be distinguished by the characters 
given below. 
EXPLANATION OF PLATE VII. 
Fic. 1.—Orconectes hamulatus Cope, twice nat. size. 1 @, antennal scale, enlarged; 
4, first gonopod. Po 
Fic. 2.—Crangonyx antennatus Packard. 2a, end of abdomen and appentsee “i 
2 6, head with base of upper, and entire lower antenna and eyes; ? % ane 
all enlarged, 
Fic. 3.—Cecidotea nickajackensis Packard (only one pair of an s . a 
upper or smaller antennz ; 3 4, end of telson with the caudal appendages 5 *° 
e . ith the 
Fic. 4.—Ceuthophilus ensifer Packard, nat. size. 44, end of abdomen, baie ee 
outer rhabdite or blade of the ovipositor bent up to show the sham ad 
toothed ovipositor, the six teeth are not well shown by the artist; 4 4, : - 
_of the body with the ovipositor. J.S.Kingsley,dele 
pies AALS can by the much > 
tenn drawn). 34 — 
a 
‘This species differs from C. stygius Scudder, of Mammoth cay curved 
more pointed sabre-shaped cuinaninans its tip being long, slender and acutely ich 
with six smaller teeth, there bei ve in large individuals of C. styg7#*» “2 : 
ovipositor is blunt, and the tip obliquely truncate, while the hind fem ee 
little longer. The e as well developed as i US. ‘plack- 
ing are much t e in the two species, both being thickly spotte 
m 
—— ength of ov | : 
20mm. It differs from C. dafeus Scudder and C. sloanii Packard in” 
_and can only be confounded with C. stygius. = . 
area 
