BULLETIN 104, UNITED STATES NATIONAL MUSEUM. 



SYSTEMATIC TREATMENT. 



Order FORAMINIFERA. 



Pseudopodia of fine thi'eads, freely auastomosiug to form a net- 

 work; tost typically with many minute foramina, in one family with 

 a single aperture; wall of the test composed of chitmous or calca- 

 reous material when secreted, or of agglutinated sand, sponge spi- 

 cules, shells, etc., usually secretmg either no silica or a very little 

 under certain conditions. 



Family 1. GROMIDAE. 



Test usually chitinous, sometimes with a covering of foreign mate- 

 rial; apertures one or more; as a rule inhabiting fresh or hracldsh 

 waters. 



As most of the material of this paper is based upon diedged mate- 

 rial and has been examined dry little opportunity has been had for 

 obtaining material of this family. Papers by Rhumbler ^ and 

 Calkins ^ may be referred to as having Atlantic data for this family. 



Family 2. ASTRORHIZIDAE. 



Test composed of agglutinated material for the most part, occa- 

 sionally with a chitinous inner layer, consisting of a chamber with 

 sev.eral openings or a tubular test open at both ends, or in certain 

 forms, of a closed chamber with a single aperture, but throughout 

 the family the test is not divided into a series of chambers. 



The species included in this family build tests of agglutinated 

 material, often placed outside a chitinous base as in RMzammina, 

 Pelosina, etc. The simplest species, such as found in the genus 

 Astrorhiza, sunply gather about the soft parts the mud or debris 

 from the bottom and agglutinate it somewhat with a small amount 

 of cement, the central chamber corresponding to the main part of 

 tlie cell and the arms to the pseudopodia. Next in order are tests 

 with definite openings and later a test closed at but one point, which 

 serves as the aperture, such as Pelosina, Pilulina, etc., or with sev- 

 eral apertures, Tlmrammina. From this the series leads to the 

 species having a definite globular proloculum or initial chamber and 

 a second chamber of greater or less length, Tlyperammina, Ammo- 

 discus, etc. 



1 Arch. Prot., vol. 3, 1903, pp. 181-294. 



'Marine Protozoa from Woods Hole, Bull. r. s. Fish. Coinni., vol. 21, 190) (1902), pp. il5-4ti8. 



