FORAMINirERA OF THE ATLANTIC OCEAN. 173 



Description. — Test elongate, composed at least in the microspheric 

 form of a series of chambers arranged tri- or bi-serially, followed 

 by a later iiniserial development ; walls hj^aline and perforate ; aper- 

 ture in the uniserial portion central and terminal, usually with an 

 elongated neck and flaring lip ; interior of the chamber with a tubular 

 connection running from the base of the apertural neck to the lip of 

 the aperture below; wall smooth or ornamented by costae, pits, etc. 



Both microspheric and megalospheric forms occur in the various 

 species of this genus. In the microspheric form the early chambers 

 are biserial or triserial, and there is usually a considerable number of 

 them before the adult uniserial development takes place. In the 

 megalospheric form the uniserial condition is taken on much earlier, 

 after only a few of the triserial or biserial chambers are developed. 



The genus seems to be limited to the Tertiary, and in the present 

 oceans is best developed in tropical waters under 500 fathoms (914 

 meters) in depth. 



SIPHOGENERINA ADVENA Cushman. 



Plate 42, fig. 15. 



Siphogenerina advena Cushman, Publ. 311, Carnegie Inst. Washington, 

 1922, p. 35, pi. 5, fig. 2. 



Description. — Test elongate, somewhat compressed, early portion 

 either triserial or biserial, later portion, which makes up the larger 

 portion of the test, uniserial ; chambers numerous, distinct, inflated ; 

 sutures somewhat depressed, the early portion and a part of the 

 uniserial portion with fine, longitudinal costae, more or less broken, 

 followed by two or three chambers slightly spinose, after which the 

 remaining chambers are smooth and very finely punctate; aperture 

 elliptical, each one connecting with the preceding by an internal 

 funnel-shaped tube. 



Length up to 0.65 mm. 



Distributio7i. — This species which was found to be common in 

 the Tortugas region of southern Florida has occurred at two 

 stations in the Albatross Atlantic collections. One of them is in the 

 western part of the Caribbean off Central America, the other off 

 the Carolina coast. This is the general distribution of many 

 species that extend throughout the West Indian region and along 

 the coast of South America so that this species probably occurs 

 widely distributed in this general region. 



Goes in 1896 ^^ gave a new name Sagrina pygmaea Goes to a small 

 species recorded by him from the Caribbean in 300 fathoms (549 

 meters). This was originally figured as '''' T extularia Pennatula, 

 var. aculeata forma Bigenerina.^^ ^* Goes's figure does not show the 



"Bull. Mus. Comp. Zool.. vol. 2D, p. 51. 



** Goes, Kongl. Svensk. Vet. Akad. Handl., vol. 19, no. 4, 18S2, p. 79, pi. 5, flgs. 

 1G5, 166. 



