300 On the Classification of the Crustacea Choristopoda, 
Subtribus I. Arcruripz, vel. Anisopopa Inorzrc ca.—Appendices due posti 
abdominales lea tz et bene o pea: appendices branchiales tegentes. 
cine dupe OL acres, vel Anisopopa OnIscica. ae tate ~~ Dn ab- 
dom plus minus e styliformes, subeerniin nales, interdum obsol 
< AE —The Am ar stege ~~ two occas di- 
visions, distinguished by the organs ‘of the mouth, the eyes and general 
habit, the Gammarus and Hype i a as lai by Edwa 
The addition of the Lesmipada - the Amphipoda introduces stig 
division. The sections are hen 
Subtribus L Carrerimea— aieaceans elongati, palpiformes, Caput oculique 
mediocres, Abdomen obsolescens, 
Subiribus I Gammarrpea.—Maxillipedes elongati, palpiformes. Caput o —— 
mediocres, Abdomen een sex aga oriis sexque styliformibus ins 
Subtribus DL Hyrpzrwra.— des abbreviati, lamellati, oe 
Caput grande, a age oe meena tectum. Appe endices abdominales ac in 
Gammarideis, latius lameliat, 
The Caprellidea os Ne habit of certain of the Anisopoda, and 
their short abdomen calls to mind the Isopoda. They therefore prop- 
erly stand first among the Amphipoda. The Caprellids like the species 
of Arcturus and Tanais, cling and stand upon seaweeds, etc., by their 
six hinder legs, while the body and the other legs are extended, for 
the purpose of capturing their food and conveying it to the mouth. 
In the following synopsis of the Families, Subfamilies ay Genera, 
some new genera - are included, discovered by the author in the course 
of the cruise of the Exploring Expedition under Capt. Wilkes. . 
TRIBUS I. 
ISOPODA. 
Subtribus I. IDOTAIDEA.* 
Fam. I. IDOTAIDA. 
Pedes fere consimiles, see minusve ambulatorii. 
G. 1, Inorma, Fabr—Ant ti onfecte. 
G. 2. Eporga, Guerin—Antenne para ioenie "pate Io ngiores, fagell pauel- 
— confect, dasi ee longiore quam basis internarum. 
G. 3. Ericusonra, Dana—An re internis pane on Ai 
E prticuaie: flagello saditek ks cag : pia 
G. 4. CiEantis, coger a ongiores, 5-6- articulate, 0 
geniculate, flagello carentes. us 4ti atiis 5 ae favienes: et 4ti 5ti Sti ri mi 
longitudine sensim inoreace ntes. Abdominis opercula laminam appendicula 
ad articulationem gereni 
G. 5. Eperys, Dana.— Antenne seg longitudine subeque; extern flagello 
- ¢arentes, non geniculate. Pedes subequi. 
Fam. 2. CHATILIDE. 
Pedes 6ti longissimi, setiformes et multi-articulati. : ‘ 
G.1. Caatmia, Dana.—Antenne 1 mz longiores, oe i 2dee flagello 
articulato to confectee. Pedes 2s 7mi breves, non unguic , Abdominis 
ee. Journal, [2,] viii, 424, 18 
