•_>!> THE ViiVACK <)F II. M.S. CHALLENGER. 



Scalpellum acutum, a. sp., dredged off Miguel Island (Azores), and off Kermadec 

 Islands (Pacific). 



Scalpellum intermedium, n. sp., dredged off Sydney and off East Cape (Auck- 

 land). 



All the other deep sea species were found only once, or at two Stations close 

 to one another (Scalpellum regium at Stations 61 and 63, Scalpellum brevecarinattnn 

 .it Stations 146 and 147). Scalpellum stroemii, Sars, is the only known deep-sea species 

 which may be called a common species over a wide area of the North Atlantic. The 

 most interesting instance of a species having a wide range, however, is Scalpellum acutum, 

 found near the Azores, and in the Pacific near the Kermadec Islands ; at both Stations, 

 however, only a few specimens were taken. Scalpellum elongation seems also to inhabit 

 the Atlantic as well as the Pacific — specimens were collected at a very different longitude 

 but almost exactly at the same latitude south in both oceans ; but the specimens of the 

 two Stations are not altogether alike, which may be due not only to the different sizes (ages) 

 of the specimens, but also to specific difference. Of course continued investigations may 

 show that what at present seems to be an exception, in reality must be considered as the 

 ride ; but with the knowledge we possess at present, we must arrive at the conclusion 

 that the deep-sea genera have a world-wide range, but that the deep-sea species ordinarily 

 have only a very limited distribution. 



There is another fact of a very puzzling nature which presents itself when comparing 

 the fossil forms with those of the deep sea. The eldest known fossil genus is the genus 

 Pollicipes, and this genus is not represented at all among the forms living at a considerable 

 depth. Yet it is by no means an extinct genus, being represented by seven living species, 

 some of which have a very wide range. But these seven species are littoral forms, at 

 least it is not recorded that any one of them was found at a depth of even 10 

 fathoms. Many of the fossil species, of which Darwin alone enumerates 22, were found 

 side by side with species of Scalpellum, which proves that the species of the two genera 

 once existed under the same circumstances of temperature, depth, &c. As the circum- 

 stances under which the fossil species lived are not known to us, and especially as we do 

 not know at what depth they existed, it is extremely difficult — not to say impossible 

 — to account for the fact that the descendants of one genus live in shallow water and 

 those of the other in deep water ; much more difficult, because in each genus the 

 fossil and the living species are specifically distinct. As the species of Scalpellum live 

 at very different depths, from the shallow water on the English and French coasts, in the 

 gulf of Naples, &c, down to almost the greatest depths where animal life has been 

 observed, we need not necessarily conclude that the deep-sea forms are those which have 

 representatives in fossil deposits ; yet it is true that the majority of the fossil species 

 of Scalpellum (all those found in Secondary deposits) have the carina simply bowed and 



