226 CORYSTOID CRABS—BENEDICT. 
‘fifth segment, in the middle 10 millimeters, and across the distal end 
10.5 millimeters. This leaves the genital opening nearly on the axis 
of a semicircle, and fully exposed. 
The females in the lot collected by Dr. Streets have these genital 
openings stopped up with a ragged looking plug, which more or less 
completely fills up the ear-like external part of these organs and even 
bulges out from them quite prominently. In most cases a tough, flat 
membrane, ragged and worn at the end, projects a little beyond the 
mass. Dissection shows that the plug extends to the point where the 
duct widens out into the seminal receptacle, where it terminates in a 
thin membranous funnel. What are these plugs, and what purpose do 
they serve? are questions which naturally arise. Are they the male 
organs? From underneath the head of the plug to the funnel-shaped 
ending the duct is exactly the same shape and size as the male organ. 
A section shows it to have the same structure. If the male organ is 
pushed in as far as it will go and detached, the flattened basal portion 
must project considerably on the outside. This portion would soon 
become broken and frayed out at the end; this could easily happen, as 
the strong armature of the genital openings would hold them without 
injury to the animal. The agitation necessary to accomplish this may 
aid the secretion of the substance of the head of the plug which so 
perfectly conforms to the parts by which itis held. A section of this 
enlarged part shows a continuation of the tougher frayed-out portion 
through the secretion. The male organ would not only stand out from 
the sternum beyond the plug, but it would extend beyond the inner end 
unless broken off or dissolved. The terminal portion of this organ is 
thin and flexible and of a different color from the posterior four-fifths. 
The organ itself is easily detached from the animal. Its loss would not 
necessarily be of great importance, as it would probably be quickly 
reproduced. 
Opposed to the supposition that this is the male organ is the fact 
that all-of the males in the collection are perfect. There are no females 
with eggs in the collection, and but one besides a collected by Dr. 
Streets in the above condition. 
This species is said to be used as an article of food by the natives of 
the Aleutian Islands. Wosnesenski (Sibirische Reise) says, however, 
that the species was not highly regarded as food, as its flesh was very 
soft. Mr. William Palmer opened the stomachs of from eight to ten 
fur seals on the killing grounds of St. Paul Island, and though their 
stomachs were nearly empty, both he and Mr. H. W. Elliott were sat- 
isfied that the contents remaining in one were shells of crabs of this 
species. The natives believe it to be eaten by this seal. 
Length of the carapace of a large specimen, 83 millimeters; width, 
102 millimeters; extent of ambulatory legs, 330 millimeters, 
