416 M. E. Hesse on the Pranizee and Ancei. 
by the author to live solely on the shore; at least they under- 
went their metamorphosis in his aquaria without having attached 
themselves to fishes: these are Anceus Brivatensis and A. Manti- 
corus. The individuals of various species kept by the author, 
some of which existed in captivity for more than two years, fed 
upon decomposed sea-weeds or upon the minute animals which 
might be met with amongst these and in the sea-water with 
which the vessels in which they were preserved were filled. 
Classification of the Ancei. 
The systematic position of the Ancez, in the author’s opinion, 
is between the parasitic Cymothoade and the Epicarides, the 
latter being, like them, suctorial Crustacea. From the Sphero- 
mide, with which they have been placed, they differ in the 
structure and arrangement of the respiratory organs, in the pre- 
sence of the large mandibles in the male, in the great size of 
the head in the same sex, in the form and structure of the an- 
tenn, and in the conformation of the buccal organs. The 
Spheromide have seven thoracic segments and seven pairs of 
thoracic limbs; in the Ancei the number of these segments and 
pairs of limbs is only five: the Ancet have a narrow abdomen, 
composed of six perfectly separate segments; whilst the Sphero- 
mide have only two or three segments in this region of the body, 
and even these are generally soldered together. The two groups 
are further distinguished by the nature of the integuments, and 
especially by the mode in which the eggs are carried previously 
to the exclusion of the young. In the Spheromide they are 
contained within the carapace ; but in the Ancez they are placed 
outside the body, beneath the membranous laminz which spring 
from within the thoracic feet and, by lying over each other, 
form a large incubatory pouch. The author also calls attention 
to the analogy presented by the female Ancez with those of 
Ourozeuktes. 
In the present. paper M. Hesse describes. eleven species of the 
genus Anceus, several of them as new; but he complains that, 
from the imperfect descriptions of previous authors, he has often 
found it impossible to identify their species. He divides them 
into four sections, characterized by the form of the large laminar 
mandibles of the males :— 
1. Mandibles in the form of nippers, denticulated only at their 
extremities. 
A. Formica; A. Brivatensis. 
2. Mandibles hatchet-shaped; their inner margins without 
denticulations. 
A. asciaferus. 
