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



word Desmoi^hilus. In the first place it is a misprint for Dfrntophilus, which should have 

 been noticed under the date 1870. la that year Beneden and Bessels, in their Mem. sur 

 la Formation du Blastoderms chez les Amphipodes, etc., p. 26, footnote, say, " JSTous avons 

 eu roecasion de constater le portionnement total du vitellus et un mode de formation du 

 blastoderme tout k fait identique k celui que nous avons reconnu chez le Gammarus locusta, 

 dans un groups d'Amphipodes tout nouveau, dont nous proposons de donner prochainement 

 la description. 



" Ces crustaoes remarquables vivent en parasites sur le Lojjhius piscatorius, et les modifications 

 qu'ont subies les caracteres du groups auquel ils appartiennent, par I'iufluence de leur 

 vie parasitique, sont d'un haut interet ;i divers points de vue. Nous proposons pour cet 

 animal le nom de Dermoplnlus loplvii. 



" On connaitra bientot des parasites dans tous les groupes de crustaces. On connait des 

 cyrrhipedes parasites en grand nombre ; certaines especes de baleines en sont litteralement 

 couvertes ; les Lern^ens sont veritablement des Copepodes parasites ; on connait depuis 

 longtemps des Isopodes parasites ; enfiu nous venons de deoouvrir un parasite qui, 

 anatomiquement comme embryogeniquement, est un veritable Amphipode." 



E. van Beneden, in the paper to which Professor Huxley refers, says at p. 132, " I'epitheleon 

 envois souvent a I'iuterieur des tubes ovariens des prolongements, en forme de cloisons 

 transversales . . . . ; quelquefois comme dans le genre Dermophilus (Ed. van Ben. et Em. 

 Bess.), ces prolongements sont de veritables lames cellulaires qui s^parent completement dans 

 le vitellogcine deu.x reufs voisins." At page 136, a footnote gives a reference, in regard to this 

 genus, to fidouard van Beneden et Emils Bessels. Mem. cour et des sav. etr. de TAcad. roy. 

 de Belg., t. xxiv.," by error for t. xxxiv. It is obvious that van Beneden applies the term 

 parasitic to any creature which lodges upon another, whether it feeds upon the carcase of 

 its host or not. It is probable that the Dermophilus lophii here mentioned is ths same as 

 the Idttlujomyzocus lophii of Eugene Hesse, 1873, while Hesse's Ichthi/omijiMcus appears 

 to be partly, if not entirely, identical with Kroyer's Lafijstius, 1842. See additional Note 

 on Hesse, 1873, in Appendix. 



For the comparative anatomy of the Crustacea, the English student will do well to read what 

 Professor Huxley has to say in this volume on all the groups, or to study his work entitled, 

 The Crayfish, an introduction to the Study of Zoology. 



1877. Martens, Eduard von. 



Crustacea. The Zoological Eecord for 1875 ; being Volume twelfth of the 

 Record of Zoological Literature. Loudon, m.dccc.lxxvii. jjp. 213-234. 



The following account is given of M. Hesse's curious new genus : — 



" Piscicolae. A new family proposed for the reception of Ichthyomyzonis, g. n.; 3 anterior jjairs 

 of feet directed forwards with hooked claws ; the 4 posterior longer, with nearly straight 

 claws ; abdomen composed of 2 or 5 segments ; respiratory organs in the form of a double 

 cylindrical multiannidated hairy rod on the under side of the abdomen ; end of the abdomen 

 two-branched, each branch terminated by several leaflets. This family connects ths 

 Amphipoda with the Jsopoda. I. ornafus, morrhuse, lopjltii, and squatinx, spp. nn., 

 living as parasites on the cod, toad-fi.sh, and angel-fish on the Atlantic coast of France. 

 Hesse, Ann. Sci. Nat. (5) svii, pp. 1-16, pi. iv. [The description is not quite satisfactory; 

 according to the position of the respiratory organ, this genus should be placed rather with 

 the Isopods than with the Amphipods.]" There seems here to be some misconception in 

 the account of the abdomen. The pleopods also, to which Hesse attributes respiratory 

 functions, are, according to his description, of the character usual among the Amphipoda, 

 not like those of Isopoda. Compare the Note on Hesse, 1873. 



