4 BULLETIN 71, UNITED STATES NATIONAL MUSEUM. 



the latter tending to assume a biserial arrangement. The test here 

 is hyaline and perforate. Two new genera have been separated 

 from the typical Bulimina to include species considerably different 

 in their characters from the genus in its restricted sense. 



The subfamily Cassidulininse includes species which are like the 

 Bulimininse in their aperture, but which have a peculiar arrangement 

 of the chambers. These are biserial, but are secondarily coiled in a 

 helicoid spiral. In Gassidulina the species are either completely 

 involute, or in late growth are somewhat uncoiled. In Ehrenbergina 

 the uncoiling takes place early, and little of the involute character is 

 seen. 



The Textulariidse as a whole are much more rich in ornamentation 

 and complicated forms than are any of the preceding families. In 

 Bollvina and in some species of Bulimina, Ehrenbergina, and Virgulina 

 there is a considerable range of ornamentation, punctse, limbate 

 sutures, knobs or bosses, costse and spines being the most common 

 forms. On the whole, however, the ornamentation is simple and 

 uninteresting compared with that seen in the Lagenidse. 



Subfamily 1. SPIEOPLECTIN.E. 



Test either coarsely arenaceous or calcareous, or even hyaline, 

 the early chambers following the proloculum closely coiled, the later 

 chambers biserial, occasionally tending to become uniserial in the 

 last developed chambers. 



This subfamily includes the single genus Sinroplecta, which in its 

 developmental stages connects the Textulariidse with the Lituolidse. 

 Its development is primitive in that the stages are seen in both the 

 microspheric and megalospheric forms of the species, and are of 

 comparatively long duration. 



Genus SPIROPLECTA Ehrenberg, 1844. 



Sinroplecta Ehrenberg (type, S. americana Ehrenberg), Monatsber. d. k. preuss. 

 Akad. Wiss., Berlin, 1844, p. 75. 



The characters are given above under the description of the sub- 

 family. The name Heterohelix was used by Ehrenberg in 1843, but it 

 is not clear whether it is entirely synonymous or not, and the type- 

 species is not clearly characterized. 



As noted above, many recent writers are referring to Spiroplecta 

 species of Textularia which show a coiled arrangement of the cham- 

 bers in the early development, especially in the microspheric form. 

 Such a treatment of these species seems to be incorrect, as previously 

 stated. Although Brady records two species of this genus from 

 Torres Strait, neither of them has been found in the material from 

 the North Pacific which I have examined. 



