174 MR EDWARD T. BROWNE ON 



processes is delineated on the top of the umbrella, which has been squeezed flat by 

 pressure in the net. 



The first specimens of this genus were described by FEWKES, 1882, under the name 

 of Halicreas minimum. These were taken in the North Atlantic off the coast of the 

 United States, between lat. 38 3 -39 N. and long. 68-71 W., and at a consider- 

 able depth. As all the specimens were in very bad condition, FEWKES'S description 

 and figures are consequently of little scientific value. He succeeded, however, in 

 establishing the genus, but not the species. 



It was left to VANHOFFEN to give the first adequate description of a Halicreas 

 (H. papillosum), which he illustrated by beautiful figures. His specimens were taken 

 on the voyage of the Valdivia, at many stations off the western coast of Africa 

 between the Canary Islands and Cape Town, and the species was again found widely 

 distributed over the warm regions of the Indian Ocean. Its chief habitat is apparently 

 the tropical regions of the Atlantic and Indian Oceans, and although once taken at 

 300 fathoms, it evidently prefers to live below 500 fathoms. In the Atlantic 

 H. papillosum was not found north of lat. 25 N., and its southernmost range in both 

 oceans was not beyond lat. 35 S. 



The geographical range of this species is important, and the southern boundary 

 appears to have been fairly well fixed by the Valdivia. This ship, after leaving Cape 

 Town, went to Bouvet Island, and then as far south as lat. 64, off Enderby Land, 

 returning across the Indian Ocean, via Kerguelen and New Amsterdam, to Sumatra. 

 Although nets were used at many stations and at great depths, yet this species was not 

 once found south of lat. 35 S. 



The Scotia specimen was taken in lat. 72, not far off the Antarctic continent, 

 which is very far outside the geographical range of H. papillosum. It is mainly for 

 the sake of geographical distribution that I have decided to establish a new variety, 

 which may attain the rank of a species when better specimens have been obtained. At 

 present the Scotia specimens can only be distinguished from those of VANHOFFEN by 

 the presence of a group of tubercles on the summit of the umbrella. 



MAAS has also described and figured Halicreas papillosum from specimens obtained 

 by the Siboga expedition to the East Indian Archipelago. Some of his specimens have 

 a cone-shaped process on the summit of the umbrella, in which they agree with 

 VANHOFFEN' s H. papillosum ; but some have an ordinary plain rounded umbrella, 

 without any ornamentation on the summit. These latter agree with FEWKES' 

 description of H. minimum, but FEWKES' specimens were in worse condition than 

 those of the Scotia. 



VANHOFFEN has placed in the genus Halicreas two other species (H. glabrum and 

 H. rotundatum) which have not got the marginal groups of tubercles. MAAS' 

 definition of the genus would exclude these two species, as he restricts the genus to 

 species with marginal tubercles. I certainly agree with MAAS in regarding the 

 marginal tubercles as a generic character. It is most probable that more than one 



(ROY. soc. EDIN. TRANS., VOL. XLVI., 238.) 



