4GO 



CRUSTACEA. 



Tribe 2. Euispoda. 



Body with seven free thoracic segments and as many pairs of 

 app&idacjes. Abdomen relatively short and broad, with abdominal 

 feet modified to form branchial lamellce. 



Fam. Cymothoidae. With biting and sucking mouth parts, broad abdomen 

 with short segments and shield-like caudal plate. The last maxillipeds in the 

 form of an operculum. They live partly as parasites on fish, and partly as 

 free-living animals. Ci/motkoa cextrnm Leach., C. cextroldex Kisso, Mediter- 

 ranean. Anilocra meditcrmncu. Leach., JEfja Incarinata Leach.. Serolis 

 paratJo.i'ti Fabr. 



Fam. Sphaeromidae. Free-living Ixopoda with broad head and short, very 

 convex body, which can often be rolled up in a ball towards the ventral side. 

 Splusroma fossarum Mont., in the Pontine marshes; nearly allied is the S, 

 granulatum of the Mediterranean. 8. srrratum Fabr., Ocean and Mediterranean. 

 It also lives in brackish water. 



Fam. Idoteidae. Free-living Isopodu with elongated body, biting mouth 

 parts, and a long caudal shield formed of several segments fused together. The 

 last pair of abdominal feet is modified to form a wing-shaped operculum for 

 the protection of the preceding branchial feet. Itlotea entomon L., Baltic. 



Fam. Asellidae. Body flattened ; the last pair of abdominal feet (pleopods) 

 are styliform (not shaped like an operculum). Jcera albifronx Mont.. British 

 seas. Aselhix (irjHiitirHx I,., fresh- water form. A. cavaticus Schiodte, in deep 

 springs. Limnona tcri'brtinx Leach. L. I'lgnorum, gnaws wood-work in the 

 sea. 



Fam. Bopyridae. Parasitic in the branchial chamber of prawns ; the body of 

 the female is disc-shaped, imsymmetrical. and without eyes. The males are 

 very small and elongated, with distinctly separated segments and eyes. Bop//rus 

 x/inillitrunt, Batr., on Palantion eyuilla. 



Here are allied the Entonlscidoe, which are parasitic in the body cavity of 

 other Crustacea {f'lrripetl ia , Pagiir'l<e, and Crabs), Gryptoniscus plananoides 

 Fr. Miill., parasitic on Xucriillnti jnn-jmrea of a Pai/urux, Brazil. Cr. pimmceus 

 Rathke, parasitic on Peltot/nxter. Entoniscux Purcrllaiifc Fr. Miill., lives 

 between the heart and the intestine of a species of Porci-llana in Brazil. 



Fam. Oniscidae. Land Isopods. Only the internal lamella (endopodites) 

 of the abdominal feet are modified to form delicate branchife. the exopodites 

 constituting firm opercula. The two anterior abdominal feet are sometimes 

 provided with air chambers. The mandibles are without palps. They live 

 mostly in damp places on land. L/f/i/i oceanica L., on stones and rocks on 

 the sea coast. Oniscux murarhix Guv., Porcellio xcnber Leach., Armadillo 

 mil/jaris Latr., A. officlnamm Brdt. 



Order 2. THORACOSTRACA.* 



Malacostraca ivith compound eyes ivhich are usually placed on 

 movable stalks, with a dorsal shield which connects all or at least 

 the anterior thoracic segments ivith the head. 



* Besides the larger works of Herbst, M. Edwards. Dana, and the essays of 

 Duvernoy, Audouin and M. Edwards, Joly, Couch, etc. compare Leach, 



