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Pleopoda well developed, adapted both for swimming and breathing. Tropoda of
a structure similar to that in the ^Egidce. Incubatory pouch composed of 5 pairs
of lamellae issuing from the bases of the 5 anterior pairs of legs ; a supplementary
pair of lamellae originating moreover from the epignath of the maxillipeds. Second
pair of pleopoda in male with a stylet inside the inner plate.
Remarks. In outward appearance, the forms belonging to this family ex-
hibit a great similarity to the ^Egidce, and were indeed formerly referred to the
very same family. They are not, however, like the latter, parasitic in character,
but lead a free existence, and it is chiefly to this difference in habits that the
apparently very different structure of the oral parts, and partly also of the anterior
pairs of legs, is due. In other anatomical characters, the close relationship between
the 2 families may be easily observed. The family has been made the subject of
a very thorough investigation by the well-known Danish zoologist, Dr. H. J. Hansen,
and the reader may therefore be referred for a more detailed description to his ad-
mirable work, in which also the nearly-allied families, Alcinoridw, Corallanidce and
Barylrotidw are treated of in detail. The following 5 genera have been included
within the present family: Cirolana, Conilera, Bathynomus, Anuropus, and Eury-
dice. Of these only the first and last are represented in the fauna of Norway.
Gen. 1. Cirolana, Leach, 1818.
Generic Characters. Body more or less elongated,
strongly vaulted and perfectly smooth. Cephalon semicircular,
with the dorsal face
with the frontal
edge evenly arched. First segment of mesosome forming on each side a lingui-
form expansion advancing over the sides of the cephalon. Coxal plates of the
succeeding segments well-defined, laminar, turned downwards. Penultimate segment
of metasome without projecting epimera; terminal segment large, more or
less narrowed distally, ciliated at the tip. Eyes placed widely apart on the sides
of the cephalon. Superior antennae very small, with the flagcllum subfusiform,
and composed of numerous very short articulations clothed with delicate sensory
filaments. Inferior antennae with the flagellum slender and elongated. Epistomal
plate very narrow. Anterior and posterior lips normally developed. Mandibles
very strong, with the cutting edge divided into a limited number of coarse teeth,
and having, inside, a distinct denticulated secondary lamella, molar expansion nar-
row, ensiform, with a regular series of small denticles along the anterior edge,
palp not very large. Anterior maxillae with the masticatory lobe very large and