On the Classification of the Crustacea Choristopoda. | 309 
2. Styli caudales 8tii minuti, viz exserti, simplices, 2di lmique ramis extus non pra- 
cipue spinosis nec cultriforinibus, interdum nudis. 
G. 3. PraroruruM, Dana.—Corpus superne visum subelliptieum, abdomine bene 
.inflexo.  Antennz flagello brevi szpe instructze, inferiores longiores, superiores 
appendiculate. Pedes mi 2dique subchelati, 2dis validioribus. Pedes 10 postici 
mediocres. 
G. 4. Cynrormmw, Dana.—.Platophio similis, Antennze superiores non appen- 
dieulatze. 
9. Styli caudales 3tii parvuli, biramei, ramo externo non uncinato, 2di 1mique ramis 
extus "on precipue spinosis nec cultriformibus. 
G. 5. Uwcrora, Say.*— Pedes 1mi 2dique manu confecti, lmis validioribus. An- 
tennz flagellis confectce, subpediformes, valide, superiores paulo longiores, ap- 
. pendieulatze. 
4. Styli caudales 3tii paulo elongati, biramei, ramo externo uncinalo.. 
G. 6. Popocznvs, Leach.f—Pedes lmi 2dique subchelati, 2dis validioribus. An- 
tennz superiores breviores, non appendiculate. [An maris digitus 2dus inter- 
dum 2-articulatus Króyero teste.] 
G. 7. OnaroPrumw, Dana.—Pedes lmi 2dique subchelati, 2dis validioribus. An- 
tennc superiores breviores, appendiculatee. 
B. picrrvs 2pUuS 2-ARTICULATUS. 
G. 8. CrnaPus, Say.—Antenne gediformes, subzeque, flagellis carentes. Pedes 
1mi 2dique prehensiles, 1mis parvulis, 2dis manu bene confectis. Styli caudales 
3tii biramei, ramis subzquis, longiuseulis. |Tubum membranaceum inhabitat. | 
G. 9. CznarPoptiNA, Edw. (Cerapus, Templeton). Antenne tote flagellis confectze. 
Pedes 4ti 5ti 6tque obsoleti(  [Tubum papyraceum inhabitat. ] 
G. 10: Enremruoxius, .Edw.]—Antenne flagellis confectzee. Pedes 10 postici medi- 
ocres, Epimerz anteriores obsolete. [An styli caudales 3tii simplieissimi ?] 
Subfam. 3. ICILINJZE.—Antenne non pediformes nec subpediformes, flagellis 
sat longis basique sat brevi instructz. Styli caudales ae in Corophinis. 
G. 1. Terums, Dona.—Pedes toti unguiculati et tenues, 4 antici longi, non prehensiles, 
' eiliati, 10 postici fere similes. Antenne superiores breviores non appendieulatee. 
G. 2. PrERYGocEnA, Latr—Pedes posteriores sublamellati. .Antenns superiores 
breviores, appendiculat:ze, inferiores basi dilatate. 
** Jour. Acad. Nat. Sci. Philad., i, 388. 
Glauconome of Króyer has the hands and antennz and apparently the other char- 
acters of Unciola. Say describes the hands of the 2nd pair in Unciola as adactyle ; 
but they still are probably like those of Glauconome. The following is Króyer's 
description :— 
* Antenne subpediformes; superiores flagello ornate appendiculari perparvo. 
Oculi minuti parum distincti. JMaudibule apex in duos fissus ramos qui dentibus 
sunt armati conicls; tubereulus molaris dentibus confertissimis instructus. Labium 
superius breve, depressum latissimum, margine anteriori medio inciso; labium infe- 
Tíus quatuor compositum laminis setosis. .JLemince maxillares pedum maxillarium 
dentibus armate validis; unguis palpi apice setosus. Pes primi paris robustissimus, 
manu subcheliformi; pes seewnd? paris gracilior, manu carens subcheliformi, pedes 
3tii, 4tique paris pergraciles; pedes 5ti, 6ti, 7mique paris graciles femoribus parum 
dilatatis. Pedes abdominales lmi 2di et 3tii paris natatorii, breves sed robustissimi ; 
4ti, btique paris saltatorii, validi; 6ti paris fere rudimentares, natatorii Epimera 
minima fere evanescentia." 
1 Jassa of Leach may without inconvenience be united to Podocerus, as there is 
no essential generic difference between them. 
i The author obtained three species in the cruise of the Expedition having the 
hands and many other characters of Erichthonius, but with the epimerals of the 
anterior thoracic segments of considerable size ; and moreover no gressorial habits 
were observed. "They are therefore with some hesitation arranged in a genus named 
, Pyetilus, aÍnong the Gammaridz, subfamily Gammaring., 
