238 Mr. R. Gurney on 
Guerne and Richard, and to A. miiller?, Richard, but?in my 
opinion there is little resemblance and no relationship between 
these species. 
So faras I amaware, A. protzi has not hitherto been found 
outside the Province of Brandenburg. 
Mesochra estuarit, sp. n. 
Female.—Body robust, the abdomen considerably shorter 
than the cephalothorax. Rostrum large and broad. Hye 
large and of a red colour. Abdominal segments entirely 
‘without spines on their dorsal surface, but the second, third, 
and fourth segments each have a lateral row of strong spines 
extending on to the ventral surface, while in the second and 
third segments there is a short mid-ventral row of small 
spines. In the fifth (last) segment the latero-ventral spines 
are small and the anal incision is margined with small spines. 
The anal operculum bears about eight small spines. The 
furcal rami are slightly longer than broad, parallel-sided. 
The outer apical seta is less than half the length of the inner 
seta, and the latter less than half the length of the body. In 
the integument of the dorsal surface of the cephalothorax and 
of the lateral surface of the first free thoracic segment there 
is a peculiar, nearly circular, transparent area bounded by a 
narrow chitinous thickening, and similar markings can be 
seen on either side of the first two segments of the abdomen. 
The first antenne are short, consisting of seven joints; the 
esthete of the fourth joint extends slightly beyond the end 
of the limb. 
The second antenna consists of three joints, the external 
branch being one-jointed, with three sete, of which the outer- 
most is considerably the shortest. 
The mandible-palp is two-jointed and bears four sete. 
The swimming-legs are of the form characteristic of the 
genus, with two-joiuted inner branches. 
First leg.—The first joint of the internal branch is longer 
than the whole of the outer branch, and its second joint bears 
an inner spine and two setze, of which one is very short and 
slender. The arrangement of the spines and sete of the 
external branch in this and the following legs is shown in the 
figures and accompanying table (p. 241). In the fourth leg 
the second inner seta of the last joint is spiniform and without 
cilia. 
Fifth leg.—The basal joint extends beyond the second joint 
and bears six sete, of which the inner two are smooth. The 
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