BIHAXG TILL K. SV. VET.-AKAD. IIANDL. BAND 1. N:0 13. 11 



Observed also on thc sca of Java (Cl) and near Xico- 

 baren Ids. (Grun). 



32. Chsetoceros decipieus Cl. X. Sp. Frustules comprcssed, 

 conuectrd into a ilat band Avith oval, not vcry large foramina. 

 Awus long, all dirccted in tbe same plane, not spinous, but 

 densely striatcd, stria^ 20—25 in 0,0 2.5 m.m. S.V. narrow 

 linear with rounded apiccs terminating in long straigbt awns. 

 Length of tbe frustule 0,O27— 0,o:54 m.m. beiglit (f. v.) 0,oi8 



— 0,0 2 5. 



Yery conimon and occurring in large massés lloating on 

 the siirface of tbe sea; Northern Atlantic Lat. 60' 25' Long. 

 19' 50' (Th. Fries) Davis Strait in many places (Lat. 61° 25' 

 —63° 30' Long 50° 50'— 53' 43'). 



Tbis spccies resembles greatly Ch. Lorenzianum Grun. 

 but is distinguished by tbe very delicate striation of tbe awns, 

 wbicb are in Cb. Lorenzianum coarsely punctated. Chret. Baeil- 

 larm Btw (M. J. IV, T. VII, fig. 1—2) diffbrs by its striated 

 membrane. 



Pl. I, fig. 5 a & b. 



33. Chsetoceros Atlanticum Cl N. Sp. Frustules com- 

 pressed, valvc in F V deeply concave and ending in long, 

 sligbtly curved awns, wbicb are densely transversely striated 

 (stiiK about 50 in 0,0 2 5 m.m.) and also bave four rows of 

 larger spincs (about 6 in 0,0 2 5 m.m.). Tbe centre of tbe 

 valve bas often a small spine. 



Lengtb of tbe frustule 0,o34 m.m. Br. (FV) 0,oi7 m.m. 

 awns measure often more tban 0,2 2 m.m. in lengtb and are 

 more conspicously spinosc towards tbe ends. 



Founcl floating on tbe surface of tbe sea: Nortbern At- 

 lantic (Lat. 60° 25' Long. 19° 50' Th. Fries) Davis Strait 

 Lat. 62° 36' Long. 52° 50'. Pl. II, fig. « <i & b. 



34. Chatoceros pelagicum Cl N. Sp. Small, scarcely sili- 

 ceous, awns very tbin and slender, not spinous. Valves deeply 

 concave, in F. V. connected into chains, baving large foramina 

 between tbe frustules. Lengtb 0,0 1 m.m. Breadtb (F.V.) 

 0,0' 8 m.m. 



Xortbcrn Atlantic (Lat. 60° 25' Long. 19° 50' Tb. Fries). 



Pl. I, fig. 4. 



