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



still greater depths ; the two species of the genus Caulophacus itself occurring near the 

 Crozets Islands and in the northern portion of the Pacific at depths of 1600 to 2300 

 fathoms, while Trachycaulus gurlittii was dredged in the South Pacific from a depth of 

 2550 fathoms. 



The Rossellidaj were represented at the well-known locality of Euplectella aspergillum, 

 ofi" the Philipjjine Island, Zebu, at a depth of 9 5 fathoms, by PolylopJms philippinensis 

 and Crateromorp>ha nieyeri. The former also occurred ofi" the Sunda and Little Ki 

 Islands at depths of 129 to 140 fathoms, along with two other species of Crateromorpha 

 and the small Lanuginella pupa; Rossella antarctica was found at similar depths in the 

 South Indian Ocean near Prince Edward and the Kerguelen Islands ; and one species 

 of the genus Bathydorus (Bathydorus stellatus), which is otherwise characteristic of the 

 greater depths, was found in the Magellan Strait at a depth of only 140 fathoms. 

 Eepresentatives of the genera Acanthascus and Rhahdocalyp>tus occurred along with a 

 Crateromorpha, Rossella antarctica, previously found in somewhat higher bathymetrical 

 regions in the Magellan Strait, two species of Aulochone, and the peculiar Euryplegma 

 auricidare, near the Kermadec Islands, at depths of 300 to 600 fathoms ; Aulocalyx 

 irregidaris w^as found at the greater depth of 1075 fathoms near the Bermudas, and at 

 1600 fathoms near the Crozets Islands. 



The maximum depth as yet known for any Hexactinellid was that of the genus 

 Bathydorus, 2900 fathoms. While Bathydorus spinosus occurred to the east of Prince 

 Edward Island at a depth of 1600 fathoms, Bathydorus fimhriatus was found about 

 20° to the east of Japan at a depth of 2300, in the middle of the North Pacific down as 

 far as 2900 fathoms. In the middle of the South Atlantic, at a depth of 2025 fathoms, 

 the peculiar species Caulocalyx tener occurred. 



The Hyalonematid found in shallowest water was Semperella schidtzei, which was 

 found off the Philij)pine Island, Zebu, in 95 fathoms, at the Moluccas, off Little Ki Island, 

 in 129 to 140 fsithoms. At the last mentioned locality two species of Pheronema were 

 also found, while the Atlantic species Pheronema carpenteri occurred to the south of 

 Pernambuco at a depth of 1600 fathoms. Of the two large species of Poliopogon, the 

 one occurred at a depth of 630 fathoms near the Kermadec Islands, the other to the 

 south-west of the Canaries at a depth of 1525 fathoms. 



There is a wide interval in the distribution of the different species of Hyalonema. 

 While several are found at depths of 345 to 390 fathoms, most of them occur below 

 1000, and thence down as far as 2550 fathoms, which is the depth attained by 

 Hyalonema (Stylocalyx) elcgans. 



The small but peculiar genus Farrea is represented at very various depths. Some 

 forms occur between 300 and 400, others not above 2600 fathoms. It is different with 

 the closely allied and externally similar Euretidse. The four different species of the 

 genus JEurete itself were all procured at the Moluccas, off Little Ki Island, from depths 



