28 ¥p. T. CLEVE. PLANKTON COLLECTED BY THE SWEDISH EXFEDITION TO SPITZBERGEN. 
Challengeria Harstonii J. Murray. 
Deep-sea hauls: 
Date. | Tat. N. Long. Depth. Fq. Pi. 
29—30 VII, 78°13? | 2°58’ W. | 2,600-Om.| + SC 
27 VII | 79°58’ | 9°35’ E. 400—0 » r SC 
| 1IX | 75°50’ | 15°25'E. | 825-0. | + S 
Habitat: The abysmal depths east of Japan. ‘ 
C. tridens Hx. 
Surface: Deep-sea hauls: 
Date. | Lat. N. | Long. Temp. Sal. Fq. Pi. Date. Lat. N. Long. Depth. Fq. Pl. 
29 VII | 77°38’ | 11°40'E.| 6 34,89 r TS 29—30 VII} 78°13’ | 2°58’ W.) 2,600—0 m.| rv cs 
1IX 762’ (13° SE] 6,61 35,13 r TS 27 VIII | 79°58’ | 9°35'E.; 400—0 » r cs 
1 Ix 75°50" | 15°25 E. | 3825—0 » r Ss 
5 IX 71°50’ | 19° 2’ E.| 230—0 > r S 
Habitat: Farée Channel. 
Challengeron Nathorstii Cr. N. sp. Shell ovate to subspherical, with a single spine 
at the apical pole, as long as the radius of the shell or longer. Diameter of the mouth 
half as long as the diameter of the shell. Structure: regular hexagonal alveoli, quincun- 
cially arranged in obliquely decussating rows (3 in 0,01 mm.). Peristome finely punctate, 
with two long and pointed, hollow, almost parallel horns, and below each of them a 
triangular or ovate hole. 
Diameter of the shell 0,06 to 0,08 mm. 
Pl. I, f. 9a. Fig. 9 d structure. 
The nearest relative is C. diodon from 
the south-eastern Pacific Ocean. 
Deep-sea hauls: 
Date. Lat. N. Long. Depth. Fq. Pi. 
27 VIL | 79°58’ 9°35’ E. | 400—O m. rr SC 
5 Ix 71°50’ | 19° 2’E. | 230—0 > ve s 
Habitat: Surface, 64° 25’ N.; 11°50’ W. 10th March 1899. 
Collozoum inerme (J. Moxt.). 
Surface: 
Date. | Lat. N.| Long. Temp. Sal. Fq. Pi. 
9 VI | 70°54’ | 20°43'E.| 7,15 34,83 y C (Ss) 
10 VI | 71°10’ |21°31/E| 6,71 35,20 c cs 
10 VI | 71°42’ | 22°35’B.| 6,40 85,15 r TC 
Habitat: Cosmopolitan, common in all warmer seas (Mediterranean, Atlantic, Indian and Pacific) HACKEL. 
— Not rare in the styliplankton of the eastern Atlantic (CL.). 
