REPORT ON THE AMPHIPODA. 49 



tliorace nudo, dorso tribus ordinibus cuspiJum notato. Descrii^tio. longitudo totius 

 animalculi, exoeptis antennis, XI linearum. Caput hemisphericum, ociili magni, protiber- 

 antes, coerulei. Os inferius situm in fouea rotundata pone insertionem antennarum, pro- 

 tuberans denticulis quatuor, quorum duo superiores, maxillam effioientes, validiorcs sunt, 

 instructum. Antennas IV. per paria dispositre : par inferius niagis validum quadriarticu- 

 latum : articulus capiti proximus breuissimus, secundus longior crassior quo complanatus, 

 tertius breuior secundo et debilior, quartus longissinius setaceus. Thorax semiouatus gibbus, 

 segmentis VI. quorum vnumquodque in medio tuberculo, vix nudo oculo conspicuo, 

 notatur ; at in vltimo segmento inferior margo euidentibus cuspidibus armatur ; reliquum 

 corpus tribus constat scutis, quorum latera sunt plana in formam semilunae efficta, in 

 abdomine appendicibus trium parium pediformibus, articulatis, extremo setaceis, instructa ; 

 in dorso autem tribus ordinibus cuspidum armata, quorum debiliores medium dorsum, 

 fortiores vero vncinnatte, latera, occupant. Pedes VII. parium, quorum duo antcriora 

 clieliformia, vnco acuto terminata, breuiora, reliqua longitudine crescunt, ita vt vltimum sit 

 longissimum, quadriarticulatum, femora latiora fere triangularia." 



" Oniscvs cvspidatvs. Tab. viii. Fig. 3. Oniscus thorace articulate, tuberculoso, segmentis 

 dorsalibus VI, cuspidatis. Descriptio. Caput j)rominulum a tliorace distinctum insequale, 

 oculis distinctis protuberant! bus. Antennas IV, quarum bases constant articvdis cylindricis 

 breuioribus, apex vero exit in setam longam attenuatam. Os inferne situm, instructum 

 maxillis bamatis euidentibus. Thorax articulatus oblongus, segmentis IV, quorum vnum- 

 quodque tuberculis III, sat eleuatis, medio oblongiore, notatur ; vltimum vero segmentum, 

 praeter tubercula, cuspidibus IV dorsum respicientibus instructum. Dorsum et abdomen 

 constant itidem segmentis IV, quae sulcis profundis atque euidentioribus distinguuntur. 

 Margo inferior anteriorum segmentorum armatur cuspidibus VI, ratione magnitudinis 

 corporis, validis, vltimum vero segmentum, uon nisi vnicam cuspidem in medio gerit. 

 Cauda in formam penicilli efTormatur ex laminibus attenuatis moUioribus. Pedes VII 

 parium, quatuor articulis constantes. Horum anteriores teneriores, hispidi; vltimi vero 

 validiores, femoribus crassioribus, complanatis. spina notatis ; abdomen tegunt tria paria 

 appcndicum pediformium, basi solidiore sulcata, apice bifido filiformi. Longitudo totius, 

 exceptis antennis, X linearum ; color lateritius ; locus, mare album." 



The first of these Arctic species was again described as a new species by Sabine in 1821, under 

 the name TuJitrus Edvardgii, which Owen in 1834 changed to Ampldtlioii Edvanlsii 

 MUne-Edwards, probably by an oversight, omitted it from his Hist, des Crustac(5s. 

 Kr0yer in 1846 fully described it, but without reference to Lepechin, under the name 

 Amphitlwe Edwardsii, while Sx^ence Bate in 1862, without 

 reference to Kr0yer, transferred it to Costa's genus AmjihitJwnoius J^O^. 3 . 



as Ampliithonotus Edwardsii. Goiis in 1865 gave it the name 

 AmpMthonotus aculeatus. Boeck in 1870 renamed it Tritropis 

 aculeata, under the impression that Costa's Ampliithonotus, 1851, 

 was preoccupied, for he says in his larger work, p. 510, "Jeg 

 har i 1870 indskrsenket denne Slasgts Omfang til do Arter, der Fig. 15. 



staa njer A. cataphradus, Stimps., og ombyttet Slaegtsnavnet, da 



det allerede forhen, i 1843, er af Fitz benyttet til et EeiitiL" Curiously enough, it is 

 Tritropis, not Amphithojiotus, which, not Fitz but Fitzinger uses for a genus of reptiles. 

 In 1883 S. I. Smith changed Boeck's Tritropis, because it was thus preoccupied, into 

 Rhachotropis. In 1874, that is, before the second volume of Boeck's last work was 

 published, Buchholz restored the name Amphitlionotus aculeatus, uniting with this species 

 Boeck's Tritropis Helleri, but retaining the name Tritropis fragilis which Boeck had given 

 to Parampliitlioii fraiiilis, Goes. Ampliithonotus, though not preoccupied, lapsed at its first 

 institution as a synonym of Dexamine. 



(ZOOL. CHALL. EXP. — PART LXVII. 1887.) XxX 7 



