REPORT OX THE AMPHIPODA. 259 



Edw.; G. 7. Cydisoma, Guerin. Subfam. 2 [3]. Synopinse. — "Corpus gracilius. Palpus 

 niandibularis sat brevis, latissimus. Oouli grandes." G. 1. SyjJo^nVj, Dana. — " Caput sub- 

 tiiangulatum, non- obloiigum. Pigmentum oculorum unicura. Pedes Imi parvuli, preheii- 

 siles; 2di setis longiusculis confecti ; 4ti subprehensiles ; 5tL 6ti Tmique subasqui." 



Fam. II. Pbroniniidffi. "Antennae 2da3 exsertas. Abdomen in ventrem se non flootens. 

 Pedes 5ti 6tive sive crassi sive. elongati, saepius preliensiles, quoque 3tii -itique ssepe 

 prehensiles." Subfam. ]. Phroniminse. G. 1. Phronima, Latr.; G. 2. Primno, Gaitin. 

 Subfam. 2. Phrosininpe. G. 1. Anchylomeva, Edw. (//ierftt-owy.r, Guerin) ; G. 2. Phrosina, 

 Risso {Dacti/lucem, Latreille); G. 3. Themisto, Guerin. Subfam. 3. Phorcinie. G. 1. 

 Phorcus, Edw. 



Fam. III. Typhidae. "Antennae 2dae sub capite thoraceve celatai et saepius replicatae. Abdomen 

 in ventrem sae.pe se flectens. Pedes 6 postici interdum abbreviati, articulo Imo operculi- 

 formi, interdum longitudine mediocres." Subfam. 1. Typhinae. — "Abdomen in ventrem 

 se flectens." G. 1. Dithyrus, Dana, — "Pedes 5ti Gtique articulo Imo late lamellati, 

 articiilis reliquis omnino obsoletis. Antennae 2dre breves, sub capite celatas, non replicatae, 

 articulo Imo longiore quam 2dus." G. 2. Tijplds, Risso. — "Pedes 5ti Gtique articulo 

 Imo late lamellati, articulis reliquis paulo abbreviatis. Antennae 2dae biplicatae, articulo 

 Imo longiore quam 2dus." G. 3. Tliyropus, Dana, "(Species Typhis ferox. (Edw.) is here 

 included)," — "Pedes 5ti Gtique articulo Imo late lamellati, articulis reliquis paulo 

 abbreviatis. Antenna; 2dae 4-5-plicatae, sub thoracis latere oelatse, articulo Imo multo 

 breviore quam 2dus." Subfam. 2. Pronoinaj. — "Abdomen in ventrem se non flectens. 

 Caput non oblongum, antennis frontalibus." G. 1. Pronoe, Guerin.— "Pedes 2di non 

 preliensiles. Pedum 6 posticorum articuli Imi lati, reliqua parte paris 7mi fere obsoleta." 

 G. 2. Lycxa, Dana. — "Pedes Imi 2dique subchelati. Articuli pedum 6 posticorum Imi 

 angusti, subaequi, reliqua parte paris 7mi paulo abbreviata." Subfam. 3. Oxycephalinaj. 

 "Abdomen in ventrem se non flectens. Caput oblongum, antennis Imis superficiem 

 capitis inferiorem iusitis." G. 1. Oxycephalm, Edw.; G. 2. Rhabdosonui, White. 



1852. Dana, James Dwight. 



United States Exploring Expedition, during the years 1838, 1839, 1840, 1841, 

 1842, under the command of Charles Wilkes, U.S.N., Vol. XIII. Part II. 

 Philadelphia. 1852. pp.689 — 1618. (Whether this Part really appeared before 

 1853 seems rather doubtful.) 



Pages 8-1 2 of Part I. contain preliminary notes on the classification of the Edi-iophthaknia. 

 In Part II. the pages refemng to Amphipoda are from 691-696, 80-5-1018, 1440-1443, 

 1518-1524,159.5-1596. 



Taking the Edriophthalmia as Subclass II. of the Crustacea, he makes the Choristopoda, or 

 Tetradecapoda, the first order of this subclass, and thus defines it : — " Cephalothorax 

 multi-annulatus, segmentis thoracis uumero septem, pare pedum utroque ad segmentum 

 .singulum pertinente, segmento anteriore cephalico brevi. Pedes thoracis pediformes, 

 saepissinie unguiculati. Abdomen paribus appendicum pluribus infra instructum. Appen- 

 dices branchiales sive thoracici sive abdominales." Of this order he makes three ilivisions, 

 the Amphipoda, Anisopoda, and Isopoda, rejecting the subdivision of Lxmipoda, 

 introduced by Latreille. "The Amphipoda," he says, "are uniformly characterised by 

 having — 



" 1. The three posterior pairs of thoracic legs in one series, and the four anterior pahs in two 

 other series of two pairs each. The branchiae are thoracic. 



