No. 26.] ARTHROSTRACA OF CONNECTICUT. I9I 



CYMOTHOIDEA Or FLABELLIFERA. ASELLOIDEA or ASELLOTA. 



Anthuridse. Asellidje. 



Cyathura carinata (Kroyer). fAsellns communis Say. 

 Ptilanthura tenuis Harger. Janiridae. 



Cirolanidae. Jara marina (Fabricius). 

 Cirolana concharum (Stimpson). bopyroidea or epicaridea. 



^gidse. Bopyrids. 



^ga psora (Linn). *Stegophryxus hypHus Thompson. 



Cymothoidas. *Probopyrus pandalicola (Packard). 

 Mgathoa oculata (Say). oniscoidea. 



Livoneca ovalis (Say). Oniscidae. 



Limnoriidas. XOniscus asellus Linn. 



Limnoria lignorum (Rathke). Philoscia vittata Say. 



Sphaeromidae. 



Sphceroma quadriden,tatum Say. XPorcellio rathkei Brandt. 



idotheoidea or valvifera. 



Cylisticus convexus (DeGeer), 



P. spinicornis Say. 



Idotheidae. JF. scaber Latreille. 



Chiridotea cceca (Say). %Mctoponorthus pruinosus (Brandt). 



C. tuftsii (Stimpson). Actoniscus ellipticus Harger. 

 *Idothea metallica Bosc. Armadillididae. 



/. baltica (Pallas). %Armadillidium vulgare (Latreille). 

 /. phosphorea Harger. Scyphacidae. 



*Scyphacella arenicola Smith. 



KEY TO THE GENERA OF ISOPODA. 

 A. First pair of legs chelate, uropods terminal. 



B. Uropods simple, short, uniramous, pleopods three pa^irs 



Tanais p. 193 



BB. Uropods biramous, pleopods five pairs Leptochelia p. 195 



AA. First pair of legs not chelate. 

 B. Uropods lateral. 

 C. Outer ramus of uropods arching over base of telson. 



D. Maxillipeds with uniarticulate palp Ptilanthura p. 200 



DD. Maxillipeds vv^ith biarticulate palp Cyathura p. ig8 



CC. Outer ramus of uropods not arching over base of tel- 

 son, and uropods not inflexed ventrally. 

 D. Abdomen of six segments. 



E. Uropods with one ramus rudimentary ...Limnoria p. 211 

 EE. Uropods with both rami well developed. 

 F. Maxillipeds with palp free and margins of last two 



joints never furnished with hooks ...Cirolana p. 203 

 FF. Maxillipeds with palp embracing distal portion of 

 buccal mass. 

 G. Both pairs of antennas with peduncle and flagellum 



well defined .ffiga p. 205 



GG. Antennje much reduced, without clear distinction 

 between peduncle and flagellum. 

 H. Head produced posteriorly in three lobes, a 

 larger median one and two small lateral 



ones .ffigathoa p. 207 



HH. Head not produced posteriorly. .Livoneca p. 209 



DD. Abdomen of two segments Sphasroma p. 212 



CCC. Uropods inflexed ventrally and valve-like. 



