620 THE AMERICAN NATURALIST. (Vor. XXXV. 
complex and difficult to explain. Fig. 3 will aid in making the 
account clear. The appendage of the second segment repre- 
sents in surface view a truncated conical flap having at its base 
a hem which is notched in the midventralline. The hem near 
the outer sides of the flap projects into two papilla, each of 
which terminates in a heavy spine. 
Projecting from the under surface 
of the hem are two pairs of large 
and one pair of small papillze, with 
their corresponding spines. This 
papillate appendage partially con- 
ceals two trowel-shaped, strongly 
chitinized, downward and backward 
directed projections of the third 
segment. The accessory glands 
| and vasa deferentia open near to- 
Frc.3.—Reproduciveappendages gether, in the median line, where 
of male K. wheeleri. 
the posterior surface of the un- 
paired appendage is continuous with the anterior surfaces 
of the paired appendages. 
Another important specific difference seems to be in respect 
to the lung sacs, organs which are evidently much more promr 
nent in the Texan species. These organs must, in fact, be 
entirely lacking in K. mirabilis, for such careful observers as 
Drs. Hansen and Sorensen could not have entirely overlooked 
them. On examination of a few of our specimens, one cannot 
fail to observe peculiar little sacs projecting from the ventral 
surface sometimes of the fourth, sometimes of the fifth, some 
times of the sixth, and occasionally from all three segments. 
Again a specimen may be found in which all six sacs are inva 
nated, giving it the appearance of possessing three pairs of 
stigmatic apertures. Of these organs Dr. Wheeler writes: " In 
many specimens a delicate sac may be found evaginated from 
under a flap on all three segments. These sacs are in all prob- 
ability lung books. They appear to be the only pease 
organs of Koenenia apart from the delicate integument, whic 
` in so. small an animal must of itself nearly suffice for pP 
tory purposes. If I am correct in regarding the above-descri 
