75 



Finally it may be added, that in those specimens of Hippolyte in whose branchial 

 cavity was found an adult female with ovisacs of Ohoniostoma , the gills belonging to the 

 two foremost pairs of trunk-legs were either somewhat reduced, or had quite disappeared, 

 and in one case the three other gills situated more behind appeared a little curled, as a 

 sign of degeneration. In one specimen, which was infested with several smaller females, 

 the gills were slightly curled. 



i. Geographical and Bathymetrical Distribution of the Family. 



Of the forty-three species described here, sixteen come from Denmark, and one of 

 these was also found at le Croisic ; eight are from Norway, eight from West-Greenland, and 

 two of these also in the Kara Sea, three only from the Kara Sea, besides the two which 

 are also found in Greenland, four from Sicily, two from the Pacific near the East-coast of 

 Asia, one from the Cape, and one from the West-Indies. It may be added that in the 

 most northern part of Norway and in the Barents Sea there has been found an undetermined 

 species of Ghoniostoma , though no doubt one of those which occur in the Kara Sea, that 

 one species (Spheeronella Leuckartii Sal.) was taken at Naples, another species (Somoeoscelis 

 sedentari a (Bonn.)) in the Atlantic offGascogne, and besides, a non-described Splicer, diadema 

 G. and B. in the Mediterranean. Without counting Norway, whose species -- with one 

 exception — have been discovered and sent me by Prof. G. 0. Sars , the number of species 

 from the different countries and seas is nearly proportional to the material which our museum 

 possesses of Amphipoda and Cumacea — the two orders in which most parasites have been 

 found — from the same localities. From this fact we can pretty safely draw the conclusion 

 that the examination of a manifold larger material than was at my disposal, e. g. from the 

 Mediterranean and from eastern Asia, will bring numerous unknown forms to light. The 

 above statements also suggest the probability that the family is distributed over all seas, 

 though of course I cannot form any precise notion how far its geographical distribution 

 will extend, when some day the chief bulk of the existing species has been discovered, for, 

 as stated in the preface, I think there can be no doubt that their number amounts to 

 hundreds. 



Unfortunately I am not prepared to give many data concerning the bathymetrical 

 extent of my species, for in most cases I lack precise indication of the depth in which the 

 special hosts have been found. Most of the sixteen Danish species and four species from 

 the Mediterranean were taken in a depth of between a few and twenty-five fathoms, but 

 unfortunately I cannot state precisely in how shallow water the most littoral species is 

 generally found, or may sometimes be found; it may be stated, however, that a specimen 

 of Bathyporeia with its parasite, Spheeronella paradoxa, was taken in a depth of between eight 

 and eighteen feet. Stenothocheres egregius was taken in a depth of forty fathoms, a few 

 specimens in a depth of between forty and sixty fathoms; my only specimen of Sphcer. 



10* 



