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298 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. 
‘“‘The ‘glandular mucosa’ [Zenker’s organ] consists of a central 
cylinder, closely beset with radiating filaments, arranged in 50 to 60 
transverse rows, the whole organ being imbedded in a sort of glairy 
matrix. The two glands are connected each by an efferent duct with 
the ‘bursa copulatrix,’ an organ of very complicated structure, and con- 
sisting of a much convoluted canal (? vesiewla seminalis), an intromittant 
organ or penis, and two hooked appendages. The whole organ is very 
dense in structure, consisting probably of chitin, deep brown in color, 
and, with the ‘glandule mucose,’ constitutes a very considerable por- 
tion of the male carapace. It should be noted that the ‘bursa copula- 
triv,’ as well as the testis,* is a double organ, one on each side of the 
median line. The two burse lie closely in apposition but are not in 
organic connection except at the upper margin, where they are held 
together by a ligamentous tissue. Length ,; in. (1.1 mm.), height. 
#, in. (0.78 mm.).’? Habitat: Minnesota (Herrick ’85). 
GENUS CANDONA Baird. 1850. 
This genus, which was founded by Professor Baird (5) has recently 
been more restricted by Mr. Wenzel Vavra (221). In this connection 
the genus is used in Vavra’s restricted sense. 
In the female the antenna is five-jointed. In the male, owing toa 
division of the fourth joint, the antenna is six-jointed. At the division 
between the fourth and fifth joints of the male antenna two character- 
istic olfactory hairs are situated. The distal extremity of the third 
joint is not supplied with a brush of natatory sete. The rudimentary 
branchial plate of the second maxilla is composed of two, unequal, 
pectinated sete, which are attached directly to the basal portion of the 
maxilla. In the female the palp of this maxilla is two-jointed, and 
terminates with three unequal pectinated bristles. In the male this 
palp, which is then unjointed, differs in shape from that of the female- 
The second foot, which may be either five or six-jointed, terminates 
with three sete; two unequally long, backwardly directed, setz and 
one forwardly dimobtied seta. 
The strong post-abdomen (abdominal ramus) pail two terminal 
claws. The seta on the caudal border of the ramus is quite remote 
from the end. At the origin of this ramus the dorsum of the body 
terminates in a short seta. The eye is small. 
Males are common, larger than the females. 
Seven circles of chitinous spines are arranged around the central 
cylinder of Zenker’s organ. The copulative organ is not so complex 
as that of Notodromas. 
*Dr. Brady uses testis as a synonym for Zenker’s organ. It isnow well known that this organ is not 
the testis. 
