— 915 — 
_ In the Gulf of Siam this characteristic species often occurs in short 
chains (4 specimens together). 
1 (mr) — 2(4) — 3(+4) — 44) — 50) — 74). 
and var. reflexa 4 (rr). 
Area: Red Sea, Indian Ocean. 
6. €. curvicorne (Daday) Cleve, Notes on some Atlantic Plankton- 
Organisms, Kg]. Sv. Vet.-Ak. Handl., Bd. 34, No. 1, p. 14; C. tripos var. 
curvicorne Daday, Termezetrajzi fiizetek, 1887 —88, Pl. Ill, figg. 4, 8, 12, 14; 
figurae nostrae 3 et 4. 
Fig. 3. Fig. 4. 
Ceratiwm curvicorne (Daday) Cleve. Ceratium curvicorne (Daday) Cleve 
Ventral view. Lateral view. 
This species seems to be abundant in the Gulf of Siam. The spe- 
cimens observed agree well with Dadays figures; but sometimes the 
curvature .of the right posterior horns is less pronounced. As shown in 
fig. 4 the ventral face of the body is concave and the basilar parts of the 
posterior horns proceed in a nearly right angle to the transversal axis. 
2(r) — 3(+) — &(+) - 5(rr) — 6(+) — 7(+) — 8x) — 10). 
Area: Warmer Atlantic, Mediterranean, Red Sea, Indian Ocean. 
