1896. ] OF THE GENUS SERGESTES. 969 
Ortmann’s, and Faxon’s specimens of S. edwardst, Kr., must be 
re-examined, as the species is collective; thus some of the localities 
given in the literature of the subject are untrustworthy and 
several others are, in my opinion, not quite certain. But the state- 
ments given above as results of my own studies of the animals prove 
with absolute certainty that at least a series of the species have a 
very wide distribution: the Atlantic northward to lat. 23°-30° N. 
and mostly to lat. 42° N., the Indian Ocean, and at least the most 
western part of the Pacific. From the other parts of the Pacific 
I have seen no material. 
Bate writes on p. 352: “The species of this genus [Sergestes] 
are chiefly oceanic”; and this is, I think, generally admitted. But 
partly according to the foregoing investigation this statement 
must be rather altered, for we must distinguish between the larve 
and the really mature forms. Almost all known larvee have been 
taken at the surface. Yet it must be remarked that at least in short 
distance from the shore some Mastigopus-species generally are met 
with in considerable depths. This is proved by Prof. Chun, who 
in 1889 (p. 538) writes on his “ S. longirostris, Bate”: “Er war 
der hiiufigste aller Sergestiden [at the Canary Islands] und fand 
sich regelmiissig in dem Inhalt der Tiefennetze. ..... Sel- 
tener erschien er an der Oberfliche.” Later on he captured 
different larger Mastiyopus-stages of S. mediterraneus, m., and 
S. areticus, Kr., with intermediate-net (“ Schliessnetz”), near 
Lesina and Ragusa at 80, 100, 400, 500, and 500-600 metres, but 
all the Mastigopus-stages of S. arcticus, Kr., are not uncommon 
near the surface in the northern area of the Atlantic. 
While all the larvae, according to our present knowledge, are 
essentially oceanic near the surface, the adult forms give another 
result. I have accepted at most 14 earlier described mature forms 
as valid species, and of these 8 species—S. inous, Fax., S. robustus, 
Smith, S. japonicus, Bate (=S. mollis, Smith), S. bisuleatus, Wood- 
Mason, S. prehensilis, Bate, S. krdyeri, Bate, S. rubroguttatus, 
Wood-Mason, and S. hamifer, And. & Ale.—have only been 
captured with trawl or dredge between 345 and 2574 fathoms. 
The other 6 species must be treated separately. 9. arcticus, Kr., 
is typically (see Metzger, Chun, and especially the long lists given 
by Smith) an inhabitant of the deep sea, and only some younger 
specimens with black eyes have been secured at the surface, and 
one single really mature specimen (the type of Kroyer) in all 
probability near the shore. Of S. henseni (Ortm.) 2 smaller 
specimens (not 3, as written by Ortmann), the largest specimen 
about 24 mm. in length, were captured with the vertical net 
between 400 and 0 m., while a much larger specimen (35 mm. 
long) was taken with the trawl from 4000 m. The depth of 
S. halia, Fax., is not recorded, as the specimens were taken with a 
submarine tow-net ; and if S. armatus, Kr., is the Mastigopus to it, 
it is certainly no surface species, as S. armatus is not very rare in 
the northern part of the Atlantic, where no adult form which can 
belong to it has been secured. S. atlanticus, M.-Edw., is very 
