200 THE VOYAGE OF H.M.S. CHALLENGER. 



subulatir, valiJae (superiores validissimse), eadem ferme pedunciili et flagelli longitiidine, sub- 

 rostro in eodeni piano positie, alteram par anterius alteram posterius. Oculi in superficie 

 capitis dorsali siti. Mandibula? angustiores, acuminatse, palpo instructse ; lamina maxilLi; 

 prioris exterior nullis divisa articulis ; pedes maxillares palpo biarticulato. Thorax latus, 

 depressus. Pes primi paris gracillimus, manu lineari, ungue elongate ; pes secundi paris 

 lirf vis, validus, manu quadrata, nngue sublaminari apice setoso. Reliqni deoem pedes validi, 

 subcheli formes, eadem ferme longitudine. Epimera mediocris magnitudinis, quartum par in 

 acumen inferne productum. Pedes natatorii elongati, pedes saltatorii debUes." The type 

 species is " Lafi/nfius Sfurumis, Kr.," at the time the species was constituted the only one of 

 the Gammarina known to be parasitic. 

 Under the heading " new species of known genera," Kr0yer here alters Milne-Edwards' definition 

 of Leucothoii, Leach, to embrace two new species which he describes, Leucofhoc <;hjpeata, 

 Kr., from Greenland, and Lmcotlwe ijlacidlis, Kr., from Spitzbergen. These, he thinks, 

 if refused admission to LeiicofJi/w, would require, not simply one, but two new genera for 

 their reception. He rightly observes that every genus founded on a single species must be 

 liable to modification in its form to include subsequent discoveries. His own two species 

 are now included in Boeck's genus Metopa, of which Leucothoii clyj'cata is the type. 

 He describes Gammarus (Jentatux, n. s., by Sp. Bate named Alenammra dentata, and 

 by Boeck transferred to Melita dentata. He reluctantly admits the separation of 

 Acantlionotus, Owen, from Amphithoe, excluding from it Acanthonoftis )iordmunnii, 

 Milne-Edwards, which Spence Bate gives as Profomedeia nordmannii. Krityer adds 

 anew species Accmtlionoius inflatus, very near to Oniscus serrcdus, O. Fabr., but "with 

 back rounded, not dentate." These two by Boeck are named Acanthonotozoma inflatwu 

 and Aranthonntozuma serratum respectively, Owen's generic name and White's alternative for 

 it, Vertumnus, being lioth pre-occupied. Kr0yer next re-describes Ischyrocerus angvipes, 

 adding a new species Iscliijrocerus latipes, both of which belong to the older Podocerus of 

 Leach, and Ischyrocerus angeipes in Bate's opinion certainly, in Boeck's doubtfully, being a 

 synonym of Podocerus cylindricus, Say. The new species " Pndocems Leachii" here described 

 was afterwards called " Ccrajms Leachii" by Spence Bate, and Cerapus difformis by Boeck. 

 To this last S. I. Smith restores its original name Erictho7iius difformis, Milne-Edwards. 

 Krrtyer notices that the male of his species is an Erichtlionius, for which reason he makes 

 that genus yield as a synonym to Podocerus. In the genus Anonyx he notes that his 

 Anonyx appendicidosiis is only the male of Anonyx higena. He has also discovered, he 

 says, that in this genus the males are distinguished from the females in that the antenna;, 

 besides being considerably longer in the lower pair, are furnished with a number of small 

 appendages, which seem to act as suckers (Sugeskaaler), by which probably the male holds 

 the female fast. Tliese had been already noticed by Milne-Edwards in 1830 on his 

 Gammarus ornafus. They have since, at Stimpson's suggestion, been called calceoU ; it is 

 now known that they are not in all species confined to the male sex, or to the lower antennfe, 

 and as they are sometimes found in both sexes, Kroj'er's explanation of their use is thought 

 untenable. He finds a similar distinction between the sexes in his new genera Opiis, 

 Phoxus and Ampelisca, considers that Amphithoe crenulata and Amphithoe inermis should 

 on this ground be considered male and female of the same species. These are united by 

 Boeck under the name Pontogcneia inermis. He attributes his discovery indirectly to 

 Captain Holboll, his suspicions being aroused by the great number of the species to which 

 Holb0ll gave names. Of these Kr0yer paired "An. sceletator" with its female "An. 

 Krijyeri," "An. velatvs" with "An. ornafus," " An. Eschrichfii" with "An.honx spec," 

 names of undescribed species which do not re-appear. In a note he expresses a regret 

 that Milne-Edwards did not retain Alihrotus cliauseieus in the genus Lysianassa and 

 transfer Lysianassa castas to the genus Anonyx. 



