383 



CRUSTACEOLOGY. 



Body short; tail bifid, with one 



Caligus produc 



•• . : U"oa. rower than the shell, the apex armed wiih two round 

 ~— ■V""*"' filaments. 

 ■ iv.15. Sp. 1. Piscinus. 

 leat'-like process. 



A very common species, attaching itself to various 

 Mi, especially the holibut (plcuroneclcs hippoglossus). 



Caligus curtus of Miiller. Monoculus piscinus of Fa- 

 bricius and Linne. Binocidus piscinus of Otho Fabri- 

 erius. 



Oniscus lutosus of Slabber. 

 f.rfcdtKtts. Sp. 2. Productus. Body elongated; tail with three 

 laminae. 



Found on the same fish with the preceding ; common 

 en the cod. 



Monoculus salmoneus of Fabricius. 

 ius of Miiller. 



:s. Argu- Genus III. Argulus. Shell oval, plain, and mem- 

 ttrs. branaceous; in front with two contractions, notclied 



behind. Eyes two, placed at a distance from one ano- 

 ther, on the sides of the anterior edge. Antennae two, 

 in some four, of a very small size, composed of three 

 joints, conic at their base, but gradually tapering to- 

 wards the apex, inserted between the eyes. Mouth 

 with aconic pectoral rostrum. Feet twelve ; the ante- 

 rior pair tubular, and somewhat hemispherical, by means 

 of which the animal attaches itself to any body; the 

 second pair conic, composed of four joints, notched at 

 their base. The other four pair double jointed, and 

 formed for swimming. 

 Argulus. Sp. 1. Argulus. Body greenish-grey. 



Binocule du gaslerostc, Geoffroy. 



Argulus dephinus, Miiller. 



Monoculus argulus, Fabricius. 



Monoadus gyrini, Cuvier. 



Binocidus gaslerostei, Latreille. 



Argulus foliaccus of Jurine. 



Inhabits fresh waters, adhering to tadpoles and fish 

 of various kinds, as carp, tench, &c. 



Observation. A most scientific paper on this speeies, 

 drguhsfoUaceus, is given by young Jurine in the An- 

 nates du Museum d'Hisloire Naiurclle for 1 806, in which 

 lie accurately describes its anatomical structure and eco- 

 nomy. Argulus charon of Miiller is merely the young 

 of Argulus foliaccus, as has been shewn by young Ju- 

 rine in the above mentioned paper. 



Family III. Phyllopoda. 



«-. Arts. Genus IV. Arus. Body soft, covered either with a 



membranaceous or semi-crustaceous shell, of a round- 

 ish-oval shape, deeply notched behind. Two moon- 

 shaped prominent eyes, placed very near each other, on 

 the anterior part of the head. Antenna? hair-like and 

 double jointed. Mandibides two, one on eacli side, 

 nearly of a cylindrical shape, very short and hollow 

 within, somewhat waved at the apex, and compressed ; 

 the extreme point notclied. Four depressed, horny, 

 transverse maxillae, two on each side, placed under the 

 mandibules. About sixty pair of lung-like feet. The 

 tail elongate, somewhat conic, truncated at the end ; 

 composed of many very short and obscure joints. 



Sp. 1. Caneriformis. The dorsal carina blunt be- 

 hind ; no lamella between the caudal seta?. 



Inhabits marshes and stagnant pools. 



Limulus palustris, Miiller. 



Monoculus apus, Fabricius. 



Apus caneriformis, LatrciHe. 



Sp. 2. Productus. The dorsal carina spined behind; 

 a lamella inserted between the caudal fins. 



Found in the same situations as the preceding species. 



Uanerifbr- 



ti.-s. 



!';*» ductus. 



Lyn- 



CEUS. 



Brachyti- 

 nij. 



Pules. 



Is the Monoculus apus of Linne, well described by Crustacea, 

 him in Fauna Suecica, ed. sec. p. 498. "- Cauda sdis ^T-Y""" - ** 

 duabus validis, interjecld lamella." 



Family IV. Monophthalma. 



Genus V. Lynceus. Eyes two. Antenna? two or 

 four in number, setaceous or hair-shaped. Feet eight 

 in number. Head exserted. 



Sp. I. Brachyunis. Antennae four; shell glob 

 tail deflexed. 



Inhabits ponds and marshes. 



Monoculus brackyurus of Fabricius. 



Lynceus brachyuriis of Latreille. 



Sp. 2. Sphwricus. Antennae two; shell globose; Spfioericus. 

 tail deflected. 



Inhabits ponds and marshes. 



Monoculus spheric us of Fabricius. 



Lynceus sphericus of Latreille. 



Genus VI. Daphnia. Miiller, Latreille. Eye one. 6. Dapunxa. 

 Head exserted. Antennae two, branched. Feet eight, 

 (or twelve). 



Sp. 1. Pulex. Tail inflected ; shell pointed behind. 



Daphnia peunala of Miiller. 



Monoculus pulex of Linne and Fabricius. 



Daphnia pulex of Latreille. 



Pulex caudatus of SehaefFer. 



Inhabits Europe. 



Genus VII. Cypris. Muller, Latreille. Eye one. 

 Head concealed under the shell. Antenna? setaceous, 

 branched, and inserted above. 



Sp. 1 . Conchacea. Shell oval, transparent, and hairy. 



Monoculus conchaceus, Linne and Fabricius. 



Cypris pubera, Miiller. 



Cypris conchaceus, Latreille. 



Inhabits -fresh waters. 



Sp. 2. Deiecla. Shell somewhat kidney-shaped, and 

 transparent. 



Cypris deiecla, Miiller. 



Inhabits Europe. 



Sp. 3. Reniformis. Shell kidney-shaped and green. 



Cypris reniformis, Dardebart de Ferussac, fils. 



Inliabits France and Britain. First described by the 

 son of Dardebart de Ferussac, in the Annates du Mu- 

 seum d'Histoirc Naturelle for lSoG. It has been taken 

 in Duddingston Loch, near Edinburgh, and in vari- 

 ous ponds in Devon, by Mr Leach. See Plate CCXXI, 

 Fig. 2. 



Genus VIII. Cytiiere. One eye. Head conceal- 

 ed. Antennae two, inserted above, and hairy. 



Sp. 1. Viridis. The shell green, kidney-shaped, and 

 tomentose. 



Cy there viridis, Mill. Ent. p. 64. tab. 7. fig. 1, 2 ; 

 Latreille, Gen. Crust, et Ins. torn. 1. p. 19. 



Cytheree verte, Latreille, Hid. Nat. des Crust, el des 

 Ins. torn. iv. p. 252. 



Monoculus viridis, Fab. Ent. Sysi. torn. ii. p. 494. 



Inhabits fuci and marine conferva; of the north of 

 Europe, 



Family V. Pseudopoda. 



Genus IX. Cyclops. Miiller, Latreille. Eye one. 

 Body elongate, ovate-conical form. Antennae two or 

 lour. Feet six or ten. 



Sp. 1 . Quadricomis. Antennae four ; tail straight 

 and bifid. 



Monoculus quadricomis of Linne, Fabricius, Donovan. 



Cyclops .quadricomis of Miiller and Latreille. 



Inhabits ditches and gently running streams of water. 



Aviymones nauplii of Miiller, is merely the young of 

 this -species, or of some other. 



CVPRJS. 



Conchacea. 



Detect;!. 



Renifor- 

 mis. 



PlLTf 



cexxr. 



Fig. 2. 



8. CvTur': r, 



Viridis. 



9. Cyclops. 



Quadricor- 



JilS. 



