DESCRIPTIVE CATALOGUE OF RECENT FORAMINIFERA. 313 



aperture a transverse slit at the end of the last segment. Section 

 shows the form and arrangement of the chambers. Length, about 1.5 

 mm. (-^g inch). 

 Locality.— Gulf of Mexico (stations 2399, 2490), 109 to 170 fathoms. 



Genus FRONDICULARIA. 



Test compressed or complanate, segments V-shaped, equitant; pri- 

 mordial chamber distinct. 



FRONDICULARIA ALATA d'Orbigny. 

 (Plate 59, fig. 1.) 



Triangular or ovate, much compressed, smooth, transparent; com- 

 mencing usually with a globular chamber, which often bears a project- 

 ing spine, the succeeding segments are V-shaped, their arms becoming 

 longer with each additional segment, so that the ends are approxi- 

 mately in line with the initial chamber. Sometimes the earlier seg- 

 ments are irregular, one arm only of the V being developed. Segments 



numerous; aperture terminal, round, with lateral fissures. Length, 

 3 mm. (£ inch), more or less. 



Locality.— Gulf of Mexico (stations 2377, 2399), 210 and 198 fathoms. 



FRONDICULARIA INiEQUALIS Costa. 

 (Plate 59, fig. 2.) 



Oval or ovate, elongate, smooth; walls thin and fragile; early seg- 

 ments somewhat irregular in form and sequence; the arms of the 

 V-shaped segments short and tapering, seldom reaching the line of the 

 initial chamber. Length, 1.5 mm. (-£ T inch), more or less. 



Locality. — North Atlantic, off coast of New York (stations 2530, 2584), 

 956 and 541 fathoms. 



Genus MARGINULINA. 



Test elongate, curved; segments nearly circular in section; aperture 

 marginal. 



MARGINULINA GLABRA d'Orbigny. 

 (Plate 60, fig. 1.) 



Short, stout, smooth, irregularly ovate, slightly curved owing to the 

 planospiral arrangement of the first three segments; the later segments 

 inflated, especially on the inner side of the curve; sutures often indis- 

 tinct, aperture more or less radiate. Section shows the form and arrange- 

 ment of the chambers. Length, 1.5 mm. (yg inch), more or less. 



Localities. — North Atlantic (six stations], Straits of Yucatan, Gulf of 

 Mexico (stations 2041, 2234, 2358, 2392, 2570, 2586, 2641, 2677), 60 to 1813 

 fathoms. 



