4 BULLETIN 1(M, UNITED STATES NATIONAL MUSEUM, 



collections from the western Atlantic. Apparently the Lagenae are 

 not nearly as abundant in the western Atlantic as they are off the 

 coast of the British Isles, and in various parts of the Pacific, but 

 where the}^ do occur they are often in considerable numbers. In such 

 cases the variability has been found to be slight. I have had con- 

 siderable amounts of European material, especially from off the 

 southwest coast of Ireland, and while there is a certain amount of 

 variation shown, the majority of specimens in most cases seem to be 

 fairly constant in their characters. Most of the species, which from 

 the literature are very widely distributed, are either smooth species 

 where there are very few characters available, or where the costate 

 or striate character has been taken as a distinctive mark without 

 reference to the general shape of the test or other characters which 

 might have been used as distinctions. I believe with a study of 

 sufficient specimens it will be possible to limit the shallow-water 

 species as definitely as any other groups. As elsewhere, the deep- 

 water species seem to be wndely distributed. 



The apertural characters have been used to distinguish different 

 groups in Lagena. Such names as Entosolenia^ Fissurina^ Phialina, 

 etc., have been used in a subgeneric sense, but until more is known 

 of the amount of true variation it does not seem best to use them. 

 Such species as L. elongata have been spoken of as " open at both 

 ends." I have been able to examine a large number of specimens of 

 the elongate forms, and while many of them have both ends open it 

 has seemed in every case to be due to imperfect preservation of the 

 specimens. In every such lot there are, when sufficiently well pre- 

 served, a few specimens which show the delicate phialine lip, and the 

 opposite end, while extended out into a very attenuate test, is closed. 

 Therefore I think that except for abnormal specimens the completely 

 preserved specimens will show that one end of the test is always 

 closed. 



In order to facilitate the use of this work as a reference guide, the 

 various species of Lagena are arranged alphabetically. The figures 

 as nearly as possible are arranged in the same order. 



As Heron-Allen and Earland are now working on a very complete 

 description of the foraminifera of the general region of the British 

 Isles, I have simply indicated the occurrence of certain British 

 species, as their work will undoubtedly make the data very complete 

 for this part of the Atlantic from which I have comparatively little 

 material. 



In its geological history the genus Lagena has been recorded as far 

 back as the Cambrian, but whether the specimens are true Lagena 

 may be somewhat of a question. 



