2908. On the Classification. of the Crustacea Choristopoda.. 
Subtribus II. GAMMARIDEA. 
[Among the Gammaridea, the author finds tbat the posterior caudal 
stylets offer important characters for distinguishing natural groups or 
genera, and upon this ground, some new genera have been recognized 
among the Corophidze and Gammaridze, and others that have been re- 
jected are sustained. "Thus Iphimedia is distinct from Amphithoe, 
JMera and Dercothoe from Gammarus, etc.] 
Fam. IL DULICHIDJE. 
Gressoriz, habitu Caprelloidee. —Corpus lineare, epimeris obsoletis. 
Pedes posteriores longi, subprehensiles. Abdomen 5-articulatum. 
G. 1. Durrcnia, Króyer.*—Pedes 5ti 6ti "mique, subzequi, 2di manu confecti. An- 
tennze quatuor longze, superiores preelongi. 
Fam.Il. CHELURIDJE. 
Corpus fere cylindrieum, epimeris mediocribus. Abdomen segmen- 
tis 4to 5toque coalitis et oblongis, stylis inter se valde dissimilibus. 
G. 1. Czzzvna, Philippi.] 
Fam. III. COROPHIDJE. 
Gressoriz, pedibus partim lateraliter porrectis. Corpus plus minusve 
depressum, sepe latum, epimeris perbrevibus, interdum obsoletis. Ab- 
domen formá appendicibusque normale.  AÁntennz scepe pediformes. 
Subfam. 1. CLYDONINJE.—Styli caudales sex simplices, subulati. 
G. 1. Crxpowia, Dana.|——Pedes filiformes, 5ti 6t1 mique, longitudine increscentes, 
1mi 92di non prehensilles. Antenne dus longs, crasse, rigidse. 
Subfam. 9. COROPHINAJE.—Antennz plus minusve pediformes. Styli caudales 
1mi 2dique biramei. i 
À. DIGITUS NULLUS 2-ARTICULATUS. 
1. Styli caudales 3tii minuti, simplices, 9di 1mique ramo externo cultriformi. 
G. 1. Conornivu, ZLotr — Antenne inferiores longiores et crassiores, flagello caren- 
tes. Pedes 2di non prehensiles, 1mis crassiores, articulo 4to latiore quam 5tus. 
G.9. SirHowccErEs, Atróyer.&—Antennz inferiores longiores, flagello carentes. 
Pedes 1mi 2dique subchelati. [Pedes 3tii 4tique articulo 4to laté obcordato. 
Tubum lapillis fragmentisque concharum formatum inhabitat. | 
*: Tids. [2], i, 512, 1845. | 
1 Arch. f. Nat. 1839 ; and G. J. Allman, Ann. and Mag. N. H. xix, 361, June, 1847. 
I Amer. J. Sci. [2], viii, 140; Zei/ius, D., on same page. 
8 Voy. Scand, etc., 1838-1840, pl. 20, f£. 1; Tidsskr. [2], i 481, 1845. Króyer in 
his description says :— kA 
* Pedes thoracici primi et 2di paris validissimi, manu instructi subcheliformi. ?Pe- 
des 3tii et 4ti paris articulo primo latissimo, laminari; articulo quarto obcordato, 
laminari, manum przebente, cujus unguis efficitur artieulo quinto subconico articuloque 
sexto aciculari. Pedes 5ti 6tique paris minutissmi, sed robusti, recurvati, articulo 
primo clavato, ungue furcato. Pedes mi paris graciles, recurvati, articulo primo 
laminari, ungue minutissimo, furcato. Pedes abdominales lmi, 2di et 3tii paris nata-- 
tori breves validissimi, parte basali latissima, rhomboidali; pedes 4ti, btique paris 
saltatorii, pes abdominalis sexti paris natatorius unica instructus lamina terminali." 
