1896.] OF THE GEHUS SERGESTES. 969 



Oi'tuiann's, and Faxon's specimens of S. edwardsi, 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 tliis is, I think, generally admitted. But 

 partly according to the foregoing investigation this statement 

 must be rather altered, for we must distinguish between the larvte 

 and the really mature forms. Almost all hnoivn larvce have been 

 taken at the surface. Yet it must be remarked that at least in short 

 distance from the shore some Mastir/ojyus-species generally are met 

 with in considerable depths. Tliis is proved by Prof. Chun, who 

 in 1889 (p. 538) writes on his " -S". lonr/irostris, Bate": " Er war 

 der liiiufigste nller Scrgestiden [at the Canary Islands] und fand 



sich regel.miissig in dem Inhalt der Tiefennetze Sel- 



tener erschieu er an der Oberllache." Later on he captured 

 dilTerent larger Mastii/opus-atages of S. mediterranetis, m., and 

 S. arcticus, Kr., with intermediate-net (" Schliessnetz "), near 

 Lesina and Ragusa at 80, 100, 400, 500, and 500-600 metres, but 

 all the Mojitiffopics-steiges 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 spc-ies, and of these 8 species — S. inous. Fax., S. rohiistus. 

 Smith, S. japonictis, Bate (=8. mollis, Smith), /S. bisulcatus, Wood- 

 Mason, S. prehensilis. Bate, S. Icroyeri, Bate, S. ruhrnguttatus, 

 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. S. 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. hetiseni (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 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 iiS. annatus, 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 



