ATLANT DEEP-SEA EXPED. 1910 VOL. Ill] 



PENEIDES AND STENOPIDES. 



Sergestes tenuiremis Kroyer. 

 S. longicollus Bate 1888. 

 S. junceus Bate 1888. 

 S. tenuiremis Hansen 1896. 



Only a single young specimen was taken during the 

 expedition, C = 7 (total length about 17 mm.), at st. 64. 

 1 sn, 100 m. w. The eyes are not black, and the sex 

 •cannot be determined. 



According to Hansen (1896) S. tenuiremis is known 

 from all three oceans, though only from their warmer 

 areas, the most northerly record being lat. 32° 16' in the 

 Atlantic. St. 64 lies in lat. 34°44'N. 



Sergestes cornutus Kroyer. 

 S. cornutus Kroyer 1855. 

 S. longispinus Bate 1888. 

 5. cornutus Hansen 1896. 



A few specimens of this species were taken in the 

 southern part of the area explored by the "Michael Sars". 

 Previously it was known from the central Atlantic as far 

 north as the latitude of Florida, and, according to Ort- 

 mann (1893), from the central Pacific. 



Fig. 1 is a drawing of the petasma. The specimen 

 is possibly not fully developed, as it is difficult to form 

 an idea about the homology of the part compared with 

 the structure found in other species. The process marked 

 b certainly corresponds to b in the petasma of S. robustus. 



Hansen, in his description of the mastigopus states 

 that the fourth segment of the abdomen does not carry 

 any spine, but in nearly all the "Michael Sars" a dorsal 

 spine is found, even up to a size of C = 4 (L = about 

 14 mm.) and where it is lacking it seems to have been 

 broken off. Fig. 2 is a drawing of a specimen 7-5 mm. 

 long (C. = 2-5). Fig. 3 is the smallest specimen in the 

 collection (C = l-4 mm.), taken at st. 49. 



St. 



Gear 



m. w. 



Number 



Sex, size 



45 



y 



2000 



1 



d" 5 



48 



1 sn 







2 



d" 4 ? 4 



49 



y 



370 



2 



? 4 © 1-4 



53 



1 sn 



200 



1 



© 3-5 



64 



1 sn 



200 



3 



© 2-6. 2-2, 2-1 



„ 



y 



300 



4 



© 2-5, 2-1,2-0, 1-9 



„ 



3 A sn 



600 



1 



© 2-9 



67 



3 /i sn 



800 



1 



© 3-3 



(6) 



(8) 





15 





Sergestes atlanticus H. Milne Edwards. 

 S. atlanticus, H. Milne Edwards 1830 

 5. frisii, Kroyer 1855. 

 5. ancylops, Kroyer 1855. 

 S. pacificus, Stimpson 1860 (fide Hansen 1896). 

 5. ovatoculus, Bate 1888. 

 5. atlanticus, do. (partim). 

 5. atlanticus, H. I. Hansen 1896 and 1903. 



H. I. Hansen in his papers of 1896 and 1903 has 

 fully discussed the synonymy, and traced the development, 

 of this species, which proves to have a world-wide di- 

 stribution in the warmer seas. During the "Michael Sars" 

 Expedition it was taken only along the southern section, 

 and mostly in the upper waterlayers, though the adults 

 seem to descend to intermediate depths. 



Table of batymetrical distribution. 



Figs. 1—3. Sergestes cornutus. 1) c? 5, st. 45, y 2000. Petasma, ( 50 A). 

 2) © 2-5, st. 64, y 300, ( 10 /i). 3) © 1-7, st. 49, y 300, («/i). 



Depth 1 ) 



Hauls 



Size (C) 



Total 



2—4 



5—7 





0—200 

 200—500 

 over 500 



18 



3 



13 



53 

 4 

 6 



36 



4 



22 



89 



8 



28 



Total.... 



34 



63 



62 



125 



*) The depth is estimated as half the length of rope ("m. w."). 



