TROPICAL PACIFIC FORAMINIFERA OF "ALBATROSS" 17 



Genotype. — By designation, Serpula (Lagena) sulcata Walker and 

 Jacob. 



Test unUociilar; aperture typically radiate, rounded or elliptical, 

 terminal, central; wall vitreous, very finely perforate, variously 

 ornamented ; chambers typically without an internal tube. SUurian (?) 

 to Kecent. 



The various species assigned to Lagena probably have several 

 different sources, and it is quite possible that the type species of the 

 genus should be placed with Uvigerina and Siphogenerina, but the 

 forms are left here under the Lagenidae, to accord with the usual 

 custom among most authors and to facilitate use in reference. 



There are in the collections from the South Pacific a great many 

 specimens which are all here referred to Lagena. This is done not 

 because numerous of these are not referable to Enfosolenia, but to 

 bring together the entire group so that they may be easily referred to. 

 The distinction between Lagena and Enfosolenia is an important one, 

 but so little has been done with a great many of the forms referred 

 to Lagena that it is difficult at this time to make the distinction that 

 will be made when further studies of this great group shall be under- 

 taken and completed by future workers. Many of the species of 

 Lagena seem to be very widely distributed, while others have very 

 definite ranges, as do other characteristic foraminifera. This is due 

 partly to the fact that with a single chamber the amount of specific 

 character is somewhat limited, being dependent on general form and 

 especially on the ornamentation of the test. This latter character 

 may vary considerably, as anyone familiar with this group will under- 

 stand. On the other hand, certain very characteristic types of orna- 

 mentation, such as those of Lagena radiato-marginata and L. wrighti- 

 ana, are so definite and distinctive that the species can hardly be 

 confused with any others. As a result, such species have compara- 

 .tively limited ranges, which conform with the distribution of numerous 

 other foraminifera. There is hardly any other group of foraminifera 

 in wliich so much is needed in the way of detailed studies in regard to 

 structure and variation. 



LAGENA MARGINATA (Montagu) 



Plate 4, Figures 9a, b, 11, 12, 14-16; Plate 5, Figures 2a, b, 4a, b, 6a, b, 8, 9 



Serpula (Lagena) marginala Walker and Boys, Test. Min., p. 2, pi. 1, fig. 7, 1784. 



Vermiculum marginatum Montagu, Test. Brit., p. 524, 1803. 



Entosolenia marginala Williamson (part), Ann. Mag. Nat. Hist., ser. 2, vol. 1, 



p. 17, pi. 2, figs. 15-17, 1848. 

 Lagena marginala Brown, IUus. Conch. Great Britain, pi. 1, figs. 30, 31, 1827. — 



H. B. Brady, Rep. Voy. Challenger, Zoology, vol. 9, p. 476, pi. 59, figs. 



21-23, 1884.— Flint, U. S. Nat. Mus. Rep. for 1897, p. 307, pi. 54, fig. 2, 



1899.— CusHMAN, U. S. Nat. Mus. Bull. 71, pt. 3, p. 37, pi. 22, figs. 1-7, 1913; 



U. S. Nat. Mus. Bull. 100, vol. 4, p. 182, 1921. 



