1895. RESULTS OF '' CHALLENGER'' EXPEDITION. 39 



the Pennatulids. Moseley introduced in this memoir the terms 

 " autozooids " and " siphonozooids " in place of "polypes" and 

 " zooids," the words used by Kolliker for the tentaculate and 

 non-tentaculate forms respectively, and these terms have since been 

 used almost exclusively by writers on the anatomy of Alcyonaria. 



S. J. HiCKSON. 



In the special reports on the Alcyonaria, the Orders of the 

 Alcyonacea and Gorgonacea were examined by Professors E. 

 Perceval Wright and Th. Studer ; that of the Pennatulacea by 

 Professor A. Kolliker. Of the Pennatulacea thirty-eight species 

 belonging to nineteen genera were found, amongst which seven genera 

 and twenty-seven species were new to science ; unfortunately 

 most of the species were represented by but one or two speci- 

 mens. With regard to the geographical distribution of this group, 

 the new forms were of great interest, both extending and confirming 

 the conclusions previously arrived at by Kolliker in his well-known 

 Monograph (1872). As to their horizontal distribution, Kolliker 

 thinks it proved that they are not distributed over all seas in a 

 regular manner ; taking the families, he shows that they seem to 

 have fairly well defined centres from which they spread more or less 

 widely ; perhaps the distribution of the Umbellulidae is the most 

 remarkable. Known for over a century from only one locality, near 

 the coast of Greenland, forms of it were found during the cruise 

 between Portugal and Madeira, in the Atlantic under the Equator, 

 west of Kerguelen Island, in the South Polar Sea, off the coasts of 

 New Guinea and of Japan, and from the middle of the North Pacific 

 Ocean. The knowledge of the vertical distribution of the group was 

 greatly increased : when Kolliker published his Monograph he was 

 justified in saying that the great majority of the species were shallow- 

 water forms ; but now the deep-sea forms are about as numerous as 

 those living near shore ; Umbelliila thomsoni, Koll. (PI. vi.. Fig. 3), was 

 found at a depth of 2,125 fathoms, and U. leptocaulis, Koll., at 2,440 

 fathoms, while several other species were found at depths exceeding 

 1,000 fathoms. 



Among the Alcyonacea, owing to their being for the most part 

 shallow-water forms, the species found were not very numerous, but 

 some extremely interesting additions were made to the Siphono- 

 gorginae, a group only described by Kolliker in 1874. The researches 

 of Moseley on Heliopova coemlea and Sarcophyton lohatum, have already 

 received due appreciation from Professor Hickson. The species of 

 the genus Spongodes collected numbered twenty-two, of which 

 eighteen were new ; four new species of Siphonogorgia are described, 

 while the new genera Paranephthya, Scleronephthya and Chironephthya 

 are established for forms nearly related to this genus of Kolliker. 



Perhaps the more remarkable species occurred among the 

 Gorgonacea, an immense number of new genera and species being 



