ANTHOSOMA. CRUSTACEA. 189 



shell ; fourteen feet, the first six unguiculated, the fifth pair 

 bifid. 



C. piscinus, Lat. Head marked with sunk lines resembling the 

 letter H ; first pair of feet short, terminated by a simple bent 

 joint ; colour whitish yellow, with darker spots. 4 lines long. 

 Found parasitical on the cod, salmon, &c Desm. Crust. 341. 



Gen. 3. ANTHOSOMA, Leach. 



Shell rounded before and behind : antennae of six joints ; ab- 

 domen narrower than the shell, with two foliaceous laminae on 

 the back, and six others under the belly ; twelve feet, the 

 beak between the first pair and the six anterior furnished with 

 hooks or nails ; extremity of the abdomen with two oviferous 

 cylindrical and elongated tubes. 



A. Smithii, Leach. Shell and setae of the tail whitish. Found on 

 a species of Squalus Desm. Crust. 335. 



Gen. 4. CECROPS, Leach. 



Body oval, depressed, covered with four fixed plates, without 

 posterior appendages ; shell coriaceous, in two parts, the an- 

 terior in the form of a reversed heart, deeply notched behind, 

 the posterior of three imbricated pieces ; antennae of two joints, 

 terminated by a single hair ; fourteen feet, the six anterior 

 unguiculated ; the fourth or fifth pair bifid ; the sixth and 

 seventh with the haunches and thighs much dilated, and 

 united in pairs. 



C. Latreillii, Leach. Inhabits the branchiae of the tunny and tur- 

 bot. Desm. Crust. 339. 



FAMILY II. LERSLEIFORMES. 



No shell ; body almost cylindrical, jointed, and having the ap- 

 pearance of a worm. 



Gen. 5. DICHELESTHIUM, Hermann. 



Body almost cylindrical, of seven segments, the first larger than 

 the others and nearly rhomboidal ; antennas filiform, of seven 

 joints ; beak placed between the legs of the second pair ; eyes 

 not distinct ; twelve feet ; abdomen of six joints, the first 

 transversely lunate, and prolonged on each side into an obtuse 

 papilla, the last almost orbicular ; terminated behind by two 

 oval vesicles. 



D. sturionis, Herm. Flesh coloured, with a brown longitudinal line 

 on each side of the body. 7 lines long. Found on the Sturgeon 

 taken in the Rhine. Desm. Crust. 337. 



