536 
W. F. PUFCELL. 
able keel and pair of muscles (6g. 3). Bertkau (’78) pointed 
out the similarity between Oonops and Harpactes as 
regards their female sexual organs (p. 371), but he does not 
describe or figure the keel and muscles (’78, pi. xii, fig. 8). 
In Segestria and Dysdera the receptaculum seems to be 
differently formed. (See Bertkau, ’75, pi. vii, fig. 12, and 
’78, pi. xii, fig. 6.) 
The lung-book in the Oonopid which I examined has 
nearly twenty leaves. Its ante-chamber differs from that of 
the Dysderidas and has the normal shape found in many 
other dipneumonous spiders, that is to say, it rises vertically 
from its pedicel but soon curves gradually forwards to form 
a long “ horn,” which is nearly horizontal in its anterior part. 
The ante-chamber is densely spined on its posterior wall, 
except along its lateral edge interiorly, Avhere a small muscle 
(corresponding to No. 11 in text-fig’. 7, p. 530) is attached. 
There is a distinct and deep epigastric (interpulmonary) 
fold, which ends laterally just behind the medial ends of the 
pulmonary spiracles, but is not continuous with them. There 
is, therefore, no canal of communication between the lung- 
books and no part of the fold is lined with spines (see fig. 2). 
As in Dysdera and Segestria, the portion of the fold 
between the eutochondrites is much deeper than the portions 
which lie laterally to these. The lateral coruers of this 
deepened part of the fold form the entapophyses to which 
the entochondrites (fig. 1, t. 8) of the ventral longitudinal 
muscles are attached. These entapophyses are somewhat 
unusual in form, their deeper part forming a solid, darkly 
staining plate (fig. 1, ec. t. 8), the anterior face of which 
serves for the attachment of the obliquely transverse muscle 
{■m. 38) connected with the keel of the receptaculum seminis, 
while the entochondrite {t. 8) is attached to the upper lateral 
edge of the plate. 
Caponiidse. — This small but very interesting family bears 
some external resemblance to the Dysderidse and Oono- 
pi dae but it differs from these and, so far as I know, from all 
other spiders as well, in four unique and remarkable anato- 
