509 



than the carpus, and gradually widening distally, palm transversely truncated, 

 dactylus in female well defined, in male obtuse and immovable. Posterior 

 gnathopoda in female considerably larger than the anterior, with the carpus 

 expanded below to a broad, setiferous lobe, propodos oval quadrangular in 

 form, and about the length of the 2 preceding joints combined, palm some- 

 what oblique, and defined below by an obtuse angle, in front of which occur 

 a few short spines; those in male enormously developed, the propodos being 

 exceedingly large and expanded, nearly triangular in outline, with the inferior 

 corner much projecting and rounded off, dactylus impinging against the inner 

 concave face of the former, so as to be quite hidden, when the leg is viewed 

 from outside. The 3 posterior pairs of pereiopoda much stronger than the 

 2 anterior, and having the basal joint rather large and regularly oval in 

 form, with the posterior edge slightly serrated, that of last pair the largest. 

 Last pair of uropoda about the length of the urosome and the last segment 

 of metasome combined, outer ramus sublinear in form, and fringed on both 

 edges with fascicles of strong spines, tip truncated and cany ing a dense brush 

 of unequal spines, inner ramus exceedingly small, and armed with but a single 

 spine. Telson extending somewhat beyond the basal part of the last pair of 

 uropoda, and divided by a deep and rather wide cleft into 2 comparatively 

 narrow lobes, each of which carries at the somewhat obliquely truncated tip 

 4 small spinules, and on a slight projection of the inner edge, 3 somewhat 

 stronger spines. Colour, according to Bruzelius, brownish. Length of adult 

 female 8 mm, of male about the same. 



Remarks. This form was first described by Montagu as Cancer 

 gammarus palmatus, and was subsequently, as mentioned above, considered 

 by Leach as the type of his genus Melita. The Gammarus Dugesii of Milne- 

 Edwards is undoubtedly the same species, and this is also the case with 

 Gammarus mcegvimanus of Sp. Bate. It is easily distinguishable from the 

 other species of the genus by the armature of the urosome, and especially 

 by the peculiar shape of the posterior gnathopoda in the male. 



Occurrence. - The only place, where I have met with this form, is 

 at Hvaloer, at the entrance of Christianiafjord, from which locatity I have 

 a single, well-preserved, female specimen. The figures of the male here 

 given are from French specimens kindly sent to me by M. Chevreux. The 

 species is now for the first time added to the fauna of Norway. 



Distribution. British Isles (Montagu), Bohuslan (Bruzelius), Kattegat 

 (Meinert), Baltic (Zaddach), Dutch coast (Hoek), coast of France (Chevreux), 

 Mediterranean (Costa), Adriatic (Heller), Azores (Chevreux). 



67 Crustacea, 



