282 REPORT OF NATIONAL MUSEUM, 1897. 



equally convex on both faces; outer edge rather sharp; septal lines 

 quite distinct; aperture a transverse slit across the inner margin of the 

 final segment; color brown; surface polished. Diameter, about 1.25 

 mm. ( oV inch.) 



Localities. — Off' coast of Maryland, Gulf of Mexico, southeast of 

 Marthas Vineyard, coast of California, (stations 2228, 2385, 2394, 2568, 

 2923), 400 to 1,800 fathoms. 



TROCHAMMINA PAUCILOCULATA Brady. 



(Plate 27, fig. 2.) 



Very small, ovoid, slightly compressed, on tlie flattened sides usually 

 exposing four segments, three of which belong to the final convolution; 

 sutures depressed; walls thin, constructed of very tine sand; surface 

 polished, brown ; aperture a short curved slit on the side and near the 

 margin of the last segment. Length, about 0.5 mm. (-g^- inch). 



Localities. — Off coast of South Carolina and southeast of Marthas 

 Vineyard (stations 2313, 2568), 99 and 1,781 fathoms. 



Subfamily LOinTTTSIlSr^E. 



Test of relatively large size, lenticular, spherical, or fusiform; con- 

 structed either on a spiral plan or in concentric layers, the chamber 

 cavities occupied to a large extent by the excessive development of the 

 finely arenaceous cancellated walls. 



Genus CYCLAMMINA. 



Test spiral, nautiloid; lenticular or subglobular; smooth externally; 

 chambers numerous, involute. 



CYCLAMMINA CANCELLATA Brady. 

 (Plates 27, fig. 3; 28, fig 1.) 



Large, nautiloid, composed of numerous segments arranged plano- 

 spirally in about four convolutions, the last of which completely 

 incloses the others; sutural lines well marked, generally wavy; sur- 

 face smooth; aperture a crescent-shaped fissure at the junction of the 

 final segment with the preceding convolution; face of the final segment 

 porous. Section shows the arenaceous walls and their cancellated struc- 

 ture, the cavities in the walls communicating freely with the chambers. 



Localities. — Gulf of Mexico, south of Long Island, west coast of 

 Patagonia, coast of British Columbia (stations 2385, 2391, 2581, 2781, 

 2860), 420 to 876 fathoms. 



CYCLAMMINA PUSILLA Brady. 



(Plate 28, fig. 2.) 



Differs from the last described species chiefly in its smaller size and 

 thinner and less conspicuously cancellated walls. Section shows both 

 these characters. Diameter, about 1 mm. (.h; inch). 



Locality, — Off' coast of Oregon (station 3080), 93 fathoms. 



