588 



the year round, bul usually nol in Large quantities. The specimens have 

 curved antapical-horn, bul vary as regards the length ol' the horns and 



the size ol" the »trunk«. [See tables.] 



IV. Silicoflagellata. 



I. DICTYOCHA Ehbg., 1838. 



87. D. fibula Ehbg., Mikrogeologie, 1854, PI. 21, Hg. 42, PI. 22, 



fig. 42. 



Owing to their small size this species and the following one have 

 only occasionally been caught in the net; found in a few specimens in 

 March and October, but is undoubtedly more common. Temperatc 

 oceanic species. 



88. D. speculum Ehbg., Abh. d. Berlin. Akad., 1838; D. aculeata 



Ehbg., Mikrogeologie, PI. 22, fig. 48; Distephanus speculum Stohr, 



Palaeontographica, 26, 1880. 



Occurs as the above species; found in samples of March, April, 

 October and November. 



V. Coccolithophoridae. 



Lohmann 's excellent monograph 1 of the organisms whieh 

 produce Ihe coccoliths, has now explained to ns these cnrious 

 bodies. He has proved that they are flagellates, and tbat they are 

 common in the planklon in the Mediterranean Sea, but owing to 

 their smallness escape thorough the gauze. I have already pointed 

 out that they are not rare in the North Atlantic Ocean (see Iagt- 

 tagelser, elc. , 1900, p. 40), but are caught only when the other 

 planklon-organisms (diatoms) occur so plentifully tbat the mesbes 

 of the gauze are filled up 2 . 



I. COCCOLITHOPHORA Lohmann, 1902. 



(Coccosphaera Wallich, 1877, non Perty 1852.) 



89. C. pelagica (Wallich) Lohm., I. c. p. 138; Coccosphaera pe- 

 lagica Wallich, Ann. Mag. Nat. Hist., 1877, p. 348, PI. 17; C. atlantica 



1 Archiv fur Protistenkunde, Bd. I, 1902, Jena. 



2 In samples from the North Atlantic Ocean collected (October — November 1899 

 by a method, invented by Dr. K. J. V. Steenstrup (cfr. Ostenfeld, Iagttagelser ole. 

 1900, p. 45) I have, besides the Coccolithophora pelagica, found various Coccolitho- 

 phoridae, viz. Syracosphaera pulchra Lohm. (59°34' N. Lat., 24° 41' W. Long.), S.me- 

 diterranea Lohm. (59°35' N. Lat., 18°39' W. Long. and eastwards to 4" li.")' W. Long.). 



