2 BULLETIN 71, UNITED STATES NATIONAL MUSEUM. 



SYSTEMATIC TREATMENT. 



A systematic presentation of the three families follows, the arrange- 

 ment of the data being the same as in preceding parts of this 

 monograph. 



Family 6. CHILOSTOMELLID^E. 



Test calcareous, conspicuously punctate, chambers inflated, ovate, 

 coiled, the chambers in various genera making up a greater or less 

 proportion of the volution; aperture a curved opening between the 

 base of the chamber and its predecessor. 



This family in the present oceans is represented by two genera, 

 Chilostomella, in which the chamber takes up 180° of the periphery 

 as added, and AUomorphina , in which it takes up typically 120°. 



Instead of being related closely to the Textulariidse this family 

 seems more closely related to the Globigerinidse in many ways. 



Genus CHILOSTOMELLA Reuss, 1850. 



Chilostomella Reuss (type, C. ovoidea Reuss), Denkschr. Akad. Wiss. Wien, vol. 



I, 1850, p. 379.— H. B. Brady, Rep. Voy. Challenger, Zoology, vol. 9, 1884, 

 p. 436. 



Description. — Test composed of a series of chambers in a coil, each 

 chamber making a half coil of 180° and embracing so that but a 

 small part of the preceding chamber is visible; wall smooth, finely 

 perforate; aperture at the inner margin of the ventral face of the 

 chamber, curved. 



This genus is unlike any others of the perforate type in its having 

 but two visible chambers, in its translucent perforate walls, and in the 

 peculiar arched aperture. It has been described as an alternating 

 series of chambers but seems to be really a coiled test in which each 

 chamber takes up 180° of the volution. 



CHILOSTOMELLA OVOIDEA Reuss. 



Plate 1, figs. 1-5. 



Chilostomella ovoidea Reuss, Denkschr. Akad. Wiss. Wien, vol. 1, 1850, p. 380, 

 pi. 48, fig. 12.— H. B. Brady, Quart. Journ. Micr. Sci., vol. 19, 1879, p. 280, 

 pi. 8, figs. 11, 12; Rep. Voy. Challenger, Zoology, vol. 9, 1884, p. 436, pi. 55, 

 figs. 12-23. — Sherborn and Chapman, Journ. Roy. Micr. Soc, 1889, p. 485, pi. 



II, fig. 12.— Egger, Abh. kon. bay. Akad. Wiss. Miinchen, CI. n, vol. 18, 1893, 

 p. 305, pi. 9, figs. 1, 2.— Goes, Kongl. Svensk. Vet. Akad. Handl., vol. 25, 

 1894, p. 53, pi. 9, figs. 512-516; Bull. Mus. Comp. Zool., vol. 29, 1896, p. 50.— 

 Sidebottom, Mem. and Proc. Manchester Lit. and Philos. Soc, vol. 54, No. 

 16, 1910, p. 14. 



Description. — Test composed of several chambers, ovoid, but two 

 visible from the exterior, increasing in size rapidly as added, but a 

 small portion of the second chamber visible; wall smooth, trans- 

 lucent, very thin, finely punctate; aperture a curved, somewhat 



