FORAMINIFEEA OF THE ATLANTIC OCEAN. 3 



The Lagenidae, as a whole, are richly ornamented, and although 

 the ornamentation may be definitely grouped into costae, spines, and 

 winglike plates, there are nevertheless combinations of these in which 

 the costae become broken into knobs, bosses, and spines, and the 

 plates variously broken into tooth-like projections, and various com- 

 binations of the diiferent types of ornamentation may occur in the 

 same species. 



In addition, the delicacy of forms and curves that appear through- 

 out the group, together with their glassy tests, makes this family 

 by far the most attractive of the various groups of Foraminifera. 



Taking the oceans as a whole, the Lagenidae are best developed 

 in tropical regions at depths of 100-500 fathoms (183-914 meters), 

 where they often reach extraordinary numbers, both in species and 

 individuals. In colder waters the number of species is usually not so 

 large, but CnsteJlaria^ N odosaria^ etc., reach a large size at similar 

 dej)ths, and often in deeper water. In certain temperate regions, 

 such as that of the British Isles, Lagena especially reaches great de- 

 velopment in shallow water. In other regions Lagena seems to be 

 found in greatest numbers from 1,000-2,000 fathoms (1829-3658 

 meters), indicating that temperature is probably a large factor in 

 their distribution. 



Subfamily 1. Lageninab. 



Test consisting of a single chamber, the aperture either ecto- or 

 entosolenian. 



This subfamily includes the single genus Lagena. 



Genus LAGENA Walker and Boys, 1784. 



Lagena Walker and Boys (type, L. globosa (Montagu)), Test. Min., 1784, 

 p. 3. — H. B. Brady, Rep. Voy. Chalicnger, Zoology, vol. 9, 1884, p. 

 440.— Chapman, The Foraminifera, 1902, p. 187.— Cushman, Bull. 71, 

 U. S. Nat. Mus^ pt. 3, 1913, p. 3. 



Description. — Test monothalamous, smooth or ornamented, gen- 

 erally flask-shaped ; aperture ecto- or entosolenian. 



The genus Lagena may be taken as the radicle from which the 

 various genera of the Lagenidae have been derived. It is single- 

 chambered, except for certain specimens which are united acci- 

 dentally, either by mechanical means or by uliusual divisions of the 

 test in growth. The genus contains a great many species and varie- 

 ties, the relationships of which, as any examination of the literature 

 will show, are in a very chaotic condition. The opinion as to the 

 limits of variation of the various species varies greatly with dif- 

 ferent authors. I have been struck with the comparative lack of 

 variability in the species observed in the examination of the ^iZia^ross 



