CRUSTACEA. 647 



Sp. Bopyrus squillarum LATB., Monoculus Crangorum FABR., LATBEILLE 

 Gen. Crust, ct Ins. Tab. n. fig. 4, fern., GUERIN Iconogr., Crust. PI. 29, 

 fig. i, RATHKE de Bopyro, Tab. i. This little animal (the male is at most 

 1 5 lines long, the female 5 lines) lives under the dorsal shield on the gills of 

 Palcemones; on the Crangones, so nearly allied to them, and often living in 

 the same situation, this Bopyrus as it seems does not occur (RATHKE). The 

 fishermen think that these parasites are young soles (Pleuronectes solea L.) 



Phryxus RATHKE. Branchiae exsert, bilobed, in four pairs. 



Sp. Phryxus Hippolytes RATHKE Beitrdge zur Fauna Norivegens, Tab. n. 

 figs, j IO , pp. 40 56. This little animal, not different from Bopyrus 

 abdominalis KBOEYER (Tidsskrift, in. 1840, pp. 102 112, 289 299, Tab. 

 i. n.) keeps to the ventral surface of Hippolyte. The full-grown female has 

 on one side only a single foot which is attached to the first segment, whilst 

 on the other side, as is usual, seven feet are found. Phryxus crangonis 

 RATHKE, ibid. Tab. i, figs. 13 15, Tab. n. figs, n, 12. 



lone LATE. Branchial feet in six pairs, exsert, filiform, arbor- 

 escent in female. 



Sp. Oniscus thoracicus MONTAGU, Transac. of the Linn. Soc. Vol. ix. p. 103, 

 PI. 3, figs. 3, 4, DESMAE. Crust. PI. 46, fig. 10, GUERIN Iconogr., Crust. 

 PI. 46, figs, i, 2 ; compare also AUDOUIN and MILNE EDWARDS Ann. des 

 Sc. nat. Tom. ix., EDWAEDS Hist. nat. des Crust. PI. 33, figs. 14, 15. This 

 species lives on the gills of Callianassa subterranea. 



Kepon DUVERNOY (Cepori). Feet unarmed, with last joint sub- 

 dilated. Abdominal feet with pinnated branchiae. 



Sp. Cepon typus, DUVERNOY Ann. des Sc. natur. 2e Se'rie, Tom. xv. 1841, 

 Zoolog. pp. no 122, PI. 4, B, figs, i u. 



Family XV. Cymothoadea. Head small. Mandibles furnished 

 with a large palp. Feet of trunk in seven pairs, either all or the 

 anterior terminated by a hook incurved and moveable. Body oval, 

 depressed. Posterior part of abdomen or tail composed of from 

 three to six segments, with last segment (pygidium) large, scutiform. 

 Feet of caudal segments lamellose ; feet of last pair terminated by 

 two oars or oval styles, exsert on each side near the pygidium. 



Comp. the article Cymothoadees by W. E. LEACH, Dictionnaire des 

 Sciences natur. xii. pp. 338 354. 



Cymothoa FABR. Antennae short, inserted under the exsert 

 frons. Eyes two, lateral, situated at the margin of head. Seven 

 pairs of feet; feet terminated by a hook incurved and moveable, 

 bent and hidden under the trunk. 



