SUMMARY OF RESULTS. 
1291 
Notes on the Geographical Distribution. — An examination of the foregoing list shows 
that of the 262 species taken in this zone between 2000 and 2500 fathoms, 133 species 
(or 51 per cent.) were taken south of the southern tropic, 122 species (or 47 per cent.) 
w'ere taken wnthin the tropics, and 99 species (or 38 per cent.) were taken north of the 
northern tropic ; while 23 species (or 9 per cent.) were found to be common to all those 
three areas, 11 species (or 4 per cent.) were common to the southern and northern areas, 
22 species (or 8 per cent.) were common to the southern and tropical areas, and 13 
species (or 5 per cent.) were common to the tropical and northern areas. 
3. Animals obtained in the Dredgings and Trawlings in Depths between 
1500 AND 2000 Fathoms. 
The Challenger dredged or trawled at 32 Stations where the depth was between 1500 
and 2000 fathoms, about 1250 specimens of invertebrates and fishes being procured, 
belonging to about 500 species and about 345 genera. The total number of species and 
genera actually described and recorded in the Zoological Eeports from the zone between 
these depths amounts to 412 species, of which 348 (or 84 per cent.) are new to science, 
belonging to 272 genera, of which 105 (or 39 per cent.) are new to science, as shown in 
the followfing list. Those species taken by the Challenger in this zone only (numbering 
249 species, or 60 per cent.) are indicated by an asterisk thus.''' The geographical dis- 
tribution of the species is indicated by the heavy letters S, T, and N, used to denote 
that the species was taken south of the tropic of Capricorn (S), hetiveen the tropics of 
Capricorn and Cancer (T), or north of the tropic of Cancer (N). 
^ Deep-Sea Keratosa : 
* Holopsamma cretaceurn, n.sp. N 
* Psammina plakina, n.g., n.sp. S 
^ Monaxonida: 
Axinella erecta (Carter). S 
* Cladorhiza moruliformis, n.sp. S 
,, (?) tridentata, n.sp. S 
* Esperella mammiformis, n.sp. S 
Esperiopsis profunda, n.sp. S 
* Meliiderma stipitata, n.g., n.sp. S 
Stijlocordyla stipitata (Carter). S T N 
Teteactinellida : 
Thenea delicata, n.sp. S 
Thenea fenestrata (Schmidt). T 
^ „ sp. (?). S 
Hexactinellida : 
Aidocalyx irregularis, n.g., n.sp. S 
* Balanella pipetta, n.g., n.Qp. S 
* Bathydorus spinosus, n.g., n.sp. S 
Caulophacus latus, n.g., n.sp. S 
Euplectella suberea, n.sp. T N 
Farrea sp. (?). S 
Holascus fibidatus, n.g., n.sp. S 
,, p>olejaevii, n.g., n.sp. S 
Hyalonema conus, n.sp. S 
,, tenue, n.sp. S 
