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 gono- 
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. /atimanus 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 Hadenecus 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 antennez and legs have the same proportions. The other 
cricket is a new species of Ceuthophilus, and may be called Cez- 
thophilus ensifer Packard.’ It is very nearly allied to C. stygius 
of Mammoth cave, but may be distinguished by the characters 
given below. 
EXPLANATION OF PLATE VII. 
Fic. 1.—Orconectes hamulatus Cope, twice nat. size. I a, antennal scale, enlarged; 
1 4, first gonopod. F 
Fic. 2.—Crangonyx antennatus Packard. 2a, end of abdomen and appendages ; 
2 6, head with base of upper, and entire lower antenna and eyes; 2c, claws; 
all enlarged, : 
Fic. 3.—Cecidotea nickajackensis Packard (only one pair of antennz drawn). 3 a, 
upper or smaller antennz ; 3 4, end of telson with the caudal appendages; all 
enlarged. 
Fic. 4.—Ceuthophilus ensifer Packard, nat. size. 4a, end of abdomen, with the 
outer rhabdite or blade of the ovipositor bent up to show the shape of the 
toothed ovipositor, the six teeth are not well shown by the artist; 4 4, the end 
of the body with the ovipositor. J. S. Kingsley, del. 
1This species differs from C. s/ygdus Scudder, of Mammoth cave, by the much 
more puinted sabre-shaped ovipositor, its tip being long, slender and acutely curved, 
with six smaller teeth, there being but five in large individuals of C. styg7zs, in which 
the ovipositor is blunt, and the tip obliquely truncate, while the hind femora are a 
little longer: The eyes are as well developed as in C. séygéus. The color and mark- 
ing are much the same in the two species, both being thickly spotted with black- 
brown; C. ezsifer has darker colors and more distinct spots than C. stygdzs, though 
the latter grows to a largersize. Length of whole body, not including the oviposi- 
tor, 22mm.; length of ovipositor, 8 mm.; of hind femur, 20 mm. ; of hind tibia, 
2zomm. It differs from C. d/eus Scudder and C. sloanzd Packard in the longer legs, 
and can only be confounded with C. stygzzus. 
Published November 5, 1881. 
