l8 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 77 



Family 2. ASTRORHIZIDAE 



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

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

 several 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 Rhisammina, 

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

 Astrorhiza, simply 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 the 

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

 definite openings and later a test closed all but one point, which serves 

 as the aperture, such as Pelosina, PUiilina, etc., or with several aper- 

 tures, Thuranimina. From this the series leads to the genera having a 

 definite globular proloculum or initial chamber and a second chamber 

 of greater or less length, Hyperammina, Ainmodiscns, etc. 



Subfamily i. ASTRORHIZINAE 



Test consisting usually of a tube open at both ends or in some 

 species of AsfrorJiiza with several tubes entering a central chamber; 

 in some species with the tube branching. 



Genus ASTRORHIZA Sandahl, 1857 



Plate I, fig. I 



Test free, flattened or tubular, composed of sand or mud loosely 

 cemented ; chamber within connecting with the exterior by the open 

 ends of the tubes or by several definite apertures in the flattened 

 forms. Most of the species live in deep or cold waters. 



Genus RHABDAMMINA Carpenter, 1869 

 Plate I, fig. 2 

 Test free, either radiate, subcylindrical or branching : wall arenace- 

 ous usually rather coarsely finished on the exterior, firmly cemented ; 

 open ends of the arms serving as apertures. The species are char- 

 acteristic of deep or cold waters and are widely distributed. 



Genus MARSIPELLA Norman, 1878 

 Plate I, fig. 3 

 Test free, tubular, cylindrical or fusiform, sometimes recurved at 

 the ends ; wall composed wholly or in part of sponge spicules, or in 



