ATLANT. DEEP-SEA EXPED. 1910. VOL. III.] 



PENEIDES AND STENOPIDES 



27 



Table of cathes. 



St. 



Gear 



m. w. 



Number 



Sex, size 



23 



1 sn 



200 



1 



?6 





»» 



y 



400 



3 



? 11, 10, 0*8 





„ 



Tr 



1250 1) 



1 



<?7. 





29 



y 



400 



1 



$9 





„ 



y 



2000 



2 



?7, c?5 





34 



y 



400 



2 



2 10, 8 





42 



1 sn 



200 



1 



$7 





V 



y 



300 



1 



?6 





45 



1 sn 



200 



1 



©3.5 





„ 



y 



300 



16 



?:3a7, 5a6, la5, d":3a7, 4a6 



mm. 



„ 



y 



2000 



1 



cf 7 





49 



y 



370 



1 



©3.1 





„ 



3 In 



3000 



1 



S 7 





51 



1 sn 



200 



3 



? 9, 6, d" 7 





n 



y 



300 



6 



5 9, 7, 7, 7, d» 7, 7, 





V 



y 



3000 



2 



? 7, 6 





53 



1 sn 







1 



©4 





n 



1 sn 



100 



1 



©3 





n 



1 sn 



200 



1 



?5 





» 



y 



300 



4 



? 7, 6, 6, d" 6 





n 



3 In 



2600 



2 



?6, ^8 





56 



y 



2000 



1 



2 10 





n 



3 In 



3000 



1 



2 10 





58 



1 sn 



200 



1 



$6 





„ 



y 



300 



1 



27 





62 



y 



300 



1 



?6 





p 



3 A sn 



2500 



1 



?6 





63 



3 In 



500-200 



3 



? 5, © 4, 4 





64 



1 sn 



200 



5 



© 3.0, 2.7, 2.3, 2.0, 2.0 





„ 



y 



300 



18 



© 2 a 3.5, 5 a 3, 5 a 2.5, 6 a 2 mm. 





„ 



y 



2000 



1 



®2.o 





67 



1 sn 



50 



1 



©1.4 





„ 



y 



200 



3 



© 3.2, 2.6, 2.0 





» 



3 A sn 



600 



2 



©4, 3 





B 



y 



1200 



3 



2 7, 5, d" 5 





88 



1 sn 



200 



1 



c?8 





15 



36 





95 





Sergestes Edwardsi Kroyer. 



5. Edwardsi Kroyer 1955. 



S. oculatus do. (mastigopus) 



5. Edwardsi Hansen 1896. 



Of this species only one specimen was taken during 

 the expedition, a mastigopus about 10 mm. in length 

 (C = 2,88), at st. 67, 1 sn. 50 m. w. 



Sergestes (Acantosoma) sp. 



PI. I, fig. 1. 



The single specimen was taken at st. 51, 1 sn, 200 

 m. w. I believe the photograph will give a better idea 

 of the specimen than a description. The total length, 

 excluding rostrum and telson is 2,5 mm. I may suggest 



that this Acanthosoma-form belongs to Hansen's group II, 

 as the zoea of S. arcticus, figured by Wasserloos (1908), 

 is of quite another type. The form of the eyes suggest 

 S. Henseni as being the adult. 



Penseidae. 



Ama/openaeus Smith 1882. 



Gennadas Bate 1888. 

 Gennadas Bouvier 1908. 

 Amaiopencsus Kemp 1910. 



Amalopenseus elegans Smith. 

 Amalopenwus elegans SMITH 1882. 

 Gennadas paivus Bate 1888. 



— .— elegans BOUVIER 1908 (ubi syn.) 

 Amalopenosus elegans Kemp 1910. 



This is one of the commonest deep-sea prawns in the 

 Atlantic; it was taken in great numbers in nearly every haul 

 made in sufficient depth, — i. e. deeper than about 400 

 metres. In all 690 specimens were taken evenly distri- 

 buted over the area investigated, excluding, of course, 

 the Norwegian Sea. It seems however from the table of 

 catches that the speeies is more abundant in the waters 

 traversed by the northern route from St. Johns to the 

 banks S.W. of Ireland, in this respect very much resemb- 

 ling the other pelagic prawn of quantitative importance, 

 Acantephyra multispina, with which it disagrees in being 

 found also in the southern portion of the area. 



In the table of bathymetrical distribution 1 ) the catches 

 from the northern and southern sections are kept apart 

 and it appears as if the species ventures to ascend a 

 trifle higher up in the water in the northern section than 

 in the southern. 





Northern section 



Southern section 



Depth 

 (metres) 



< 5 mm. 



5 mm. - 



< 5 mm. 



5 mm. - 





Day 



Night 



Day 



Night 



Day 



Night 



Day 



Night 



200—375 





1 









3 



10 



3 



450-850 



253 



2 



100 



4 



14 



36 



6 



14 



1000—2100 



29 





85 



2 



23 



14 



32 



38 



It appears also that the young come somewhat higher 

 up than the adult, though they are also decidedly dwellers 

 of the deeps, even the smallest specimens in the collection 

 displaying a similar red colouring as the adult, only the legs 

 being more transparent. Even the smallest (C = 2 mm.) 

 have gone through the whole metamorphosis. The larvae, 

 which are presumably very small, could not be detected 

 in the collections. 



') Actual depth sounded. 



J ) St. 10 and vert, hauls not considered. 



