REPORT ON THE AMPHIPODA. 279 



The new genua Ptiloclicirus is thus defined : — " Body broad, as in the Coroplddx ; epimera large 

 and strong, much higher than broad. Mandibles with greatly elongated palpi ; maxillipeds 

 with their internal lamolke of half their own length. Superior antonniv appeudioulate, 

 inferior ones subpodiform. Logs of the first pair subohelate, very thick and strong 

 throughout their length, in the male ; those of the second pair plumose, without hands, 

 but minutely unguiculate ; those of the third and fourth pairs small, slender, and tapering, 

 with the last three articles forming a kind of hooked finger, but with no dilated hand ; 

 posterior three pairs strongly unguiculate ; those of the last pair much the longest. Caudal 

 stylet.? all biramous, those of the first two pairs with a strong spine projecting from 

 the inferior apex of the peduncle, along with the rami." 



"This genus resembles in most characters Leptochirus, Zaddach, and may perhaps prove 

 the same ; that name, however, is preoccupied in insects. It has relations with the 

 Pontoporinx in its plumose hairs, and somewhat in the structure of the legs of the third 

 and fourth pairs ; while it also approaches those genera of the Gammarinx which recall 

 the Coruplii.dae." Since, however, Zaddaoh's genus was not, as Stimpson spells it, Lepto- 

 chirus, but Leptocheirus, Boeck seems to have done rightly in giving it precedence, so 

 that PHIocheirus jmiguis, which Spence Bate has named Protomedeia pinguis, will now 

 stand as Leptocheirus p>inguis. 



The new genus Pseudophthalmus, or as Stimpson spells it, Psevdopthalmus, is thus defined : — 

 " Body greatly compressed, with large epimera. Head with an irregular deposition of 

 blackish or reddish pigment anteriorly, in which are one or two orbicular clear spots on each 

 side, without facets. Maxillipeds with five articles, of which the terminal one is oval ; 

 internal lamellaj with combs of spines at their apices. Mandibles palpigerous. Autennte 

 very slender, the superior ones with their basal articles much thickened, and without 

 accessory flagella ; inferior ones arising much behind the bases of the superior ones. Legs 

 of the first and second pairs sometimes with small subcheliform hands, shorter than the 

 antepenult segment, but often simply unguiculate ; those of the third and fourth pairs 

 elongated, tapering, with their second joints very small, the third expanded into a hand ; 

 posterior pairs short ; last pair with very broad basal joints. Caudal stylets all biramous. 

 Tail terminating in a thin lamella. Epimera and third and fourth pairs of legs with plumose 

 setse along their edges." 



This genus had already been described by Kr0yer under the name Ampeh'sca. The briefly de- 

 scribed type species, Pseudophthaliinis peJagicus, has become, therefore, Ampelisca pelagica. 

 Pseudophthalmus limicola, according to Boeck, is obviously synonymous with Ampelisca 

 tenuieornis, Lilljeborg. Spence Bate describes further from Grand ilanan, " Psemlop>hthcdmiis 

 ingens, Stimpson, MS.," which he had received from the author. Being an inch and a half 

 in length, it is well named Ampelisca ingens. Phoxus fusiformis is identified by Spence 

 Bate with Plioxtis plumosus, Kr0yer, which Boeck places in his genus Harpinia. " Phoxus 

 Kroyeri " of Stimpson Spence Bate accepts, renaming his own later " Phoxtis Kroyeri," Phoxus 

 simplex. Boeck, on the other hand, gives up " Phoxus Kroijeri," Stimpson, as insufficiently 

 described. 



1854. Williams, Thomas. 



On the Mechanisin of Aquatic Respiration and on the Structures of the Organs 

 of Breathing in Invertebrate Animals. The Annals and Magazine of Natural 

 History. Vol. XIII. Second Series. London, 1854. 



On page 294 he discusses Chithie. On page 295 he says, " Every Crustacean is a water-breathicg, 

 every Insect an aii-breathing animal. To this rule there can be found no real, many 



