REPORT ON THE AMPHTPODA. 179 



aliquuntulum emarginata." This is followed by a sharp criticism of the generic character 

 given by Owen for Aranfhosoma. " Amphithoe Serra Kr. (Oniscus serratus, Fabr. Fn. 

 gr. n. 237), (Tab. II, fig. 8.)" is now Acanthonotosoma serratum. Kr0yer changed )!crfafux 

 to sen-a to avoid disi)\a.cmg Aiyij^MtJioii serrata, Saj. "Amphithoe panopla Kr. (Tab. II, 

 fig. 9)." has since been called Pleu^ies panoplus. '^Amphithoe hinispis Rhrdt (Tab. 11, 

 fig. 10).," has been referred successively to Paramphithne, Amphithopsis, Fherusa, and 

 PZewsfes, and is restored by G. 0. Sars in 1882 to Paramphithoe. " Amphifhoe inermis 

 Rhrdt. (Tab. Ill, fig. 11) (Oniscus Cicada Fabr. Fn. gr. n. 2.331).," together with ''Amphi- 

 thoe crenulata RlinU (Tab. Ill, fig. 12). (Oniscus abyssinus Fabr. Fn. gr. n. 236?i)-i" 

 has been already mentioned in the note on Otto Fabricius, 1780, as now bearing the name 

 Pontoijeneia inermis, Kr0yer. "Amphithoe Ixviusnda Kr. (Tab. Ill, fig. 13).," is now 

 called Calliopius Iseviusculus. " Isrhi/rocerus angnipes Kr. (Tab. Ill, fig. 14).," is now 

 known as Podocerus angvipes, Kr0yer, though not without the admission that it may be 

 identical with the earlier Podocerus cylhidricus, Say. 



The new genus Ischyrocerus is thus defined: — " Mandihulx magnis innfrudx pal pis 

 qvorum ultimus articulus oiovatiis, fere truncatus ; antennx pediformes; pedunculus 

 (o : pars hasalis) antennarum midto longior flageUo (o : parte terminali), quod perpaucis 

 modo gaudet articulis ; antennx siiperiores fiiagello appendicular i hrevi, u n i- 

 articulato oriiatse ; pedes primi parts minuti sed validi, nianwyiqve gm'entes ; pedes 

 secundi p)aris viazimi, manu portentosx in adidtis magnitudinis armati ; reliqvi pedes solito 

 ferme more conformati ; pedes spurii qvarti, quinti Sf sexti paris saltatorii ; articulus 

 hasalis sexti paris articulis terminalibus triplo vel quadruplo longiirr ; annuli ahdominales 

 ires anterim-es annidis thoracis breviores ; epimeri mediocris magnitudinis." The name 

 Iscltyrocerus is a synonym of the earlier Podocerus. 



" Metoecus Medusarum Kr. (Tab. III. fig. 15). (Oniscus Medusarum Fabr. Fn. gr. n. 232).," 

 was transferred by Boeck to Dana's genus Tauria, the name Metoecus being pre-oecupied. 

 Bovallius, however, argues that the species cannot properly be separated from Hyperia, and 

 the sisecific name medusarum being pre-occupied in that genus, he calls the present species 

 "Hyperia Kroeyeri." But if G. O. Sars, 1882, be right in identifying Tauria ahyssorum, 

 Boeck, with the so-called Tauria medusarum, the species wiU by the law of priority become 

 Hyperia abyssorum. The genus Metoecus is thus defined by Kroyer : — " Pedes primi ef 

 secundi paris reliqvis permuUo breviores, sed validi, manuqve armati cheliformi. 

 Articidus horum pedum quartus qvi forma prxditus est triangulari, manum efficit, a cujus 

 margine inferiori prrodeunt pollex biarticularis anterior et digitus posterior. Primus pollicis 

 articulus (v. qvintus pedis) magnus, conicus ; secundus ungvis est pusillus. Digitus conicus, 

 imllice aliqvantillum brevior. Margn utriusqve p)ollicis articidi posterior, margoqve digiti 

 anterior pjer totam longitudinem scrrati. Cetera cum genere Hijpieria ferme conveniunt." 



"Themisto arctica Kr. (Themisto Gaudichaudii Ross.). (Tab. IV, fig. 16).," and " Themisto 

 crassicornis Kr. (Tab. IV, fig. 17).," are by Boeck both made synonyms of Tliemisto 

 lihellula, Mandt. Kivyer himself felt he had grounds for believing that his Tliemisto 

 arctica was not identical with "Themisto Gaudichaudii Guerin," but that it might well lie 

 so with "Ross's Themisto Gaudichaudii." 



" Lestrigonus exulans Kr. (Tab. IV. fig. 18)," is considered by Boeck and others to be the male 

 of Hyperia medusarum, O. F. Midler. F. H. Streets would keep the genus Lestrigonus 

 distinct from Hyperia. "Hyperia ohlivia Kr. (Tab. IV. fig. 19)," is also held to be 

 a synonym of Hyperia medusarum, O. F. M. 



The second part of this work is concerned with Crustacea outside the order of Amphipoda. 

 In the third part Kr0yer reviews the Greenland Crustacea in general, naming, among the 

 fifty-eight species which, he says, had come under his own observation, the Amphipod.« 

 already discussed, which are numbered from 11 to 31 in the series. Under number 38 he 



