02 BULLETIN (iO, UNITED STATES NATIONAL MUSEUM. 



Otherlocalities.—^o. 32899, U.S.N.M. Albatross Station 2041, north 

 latitude 39° 22' 50", west longitude 68° 25', near the preceding station, 

 in 1,608 fathoms, globig-erina ooze. 



The capitulum is pointed-oblong, ventricose in the lower half, the 

 occludent and carinal borders about equally convex, the total length 

 about twice the greatest width. The plates are sculptured with line, 

 close, radiating impressions and distinct concentric wrinkles and spaced 

 grooves. These are much closer on the terga and carina than on the 

 scuta. The basal orifice is rounded-pentagonal, a little longer than 

 wide. 



The very large scutum has an evenly arched occludent border. The 

 tergal margin is straight, the carinal convex, except near the base, 

 where it is somewhat concave or hollowed out, to receive the enlarged 

 side of the carina. The basal margin is short and straight. There is 

 a depression running obliquely from the umbo to the concavity of the 

 carinal margin. A subacute ridge runs from the umbo to the apical 

 angle, defining a very narrow lanceolate area along the occludent mar- 

 gin. Another much less acute ridge runs to the tergo-carinal angle. 

 The interior shows a small but prominent umbonal tooth in each (right 

 and left) valve, and a small smooth basal area, which under a strong- 

 lens has very fainth' traced radial and growth striae (Plate VII, fig. 3.) 

 A small cavity extends from above under the umbonal tooth. 



The tergum is trapezoidal, the carinal edge parallel to the occlu- 

 dent, and nearly half as long. 



The carina is short, only slighth^ arcuate. Its roof is rather wide 

 and flattened above. The sides are narrow above, but wider below 

 the middle, and in the lower third it expands into a wide plate. The 

 basal margin is straight, whether viewed from the side or back. In 

 basal view the sides are seen to form a right angle. When detached 

 the inner face of the carina is seen to be deeply concave throughout. 

 A prominent septum or sheath, bilobed and projecting above, occu- 

 pies slightly more than the lower fourth of the length. The cavity of 

 the plate penetrates behind this septum to the apex. 



The peduncle is very short, so short that the capitulum appears to 

 be sessile. 



Length of the capitulum 19, width 10, greatest diameter 5 mm.; 

 length of the carina 12 mm. 



Two other individuals of the type lot measure: Length of capitulum 

 16.5, width 8, diameter 4 mm.; length of carina 10 mm. Length of 

 capitulum 16.2, width 8, diameter 3.8 mm.; length of carina 9.7 mm. 



A very large detached scutum from the type locality measures 23 

 mm. long, indicating a larger size than any other known P<Kcil((sma. 



The single specimen from Station 2041 measures: Length of capitu- 

 lum 16.9, width 8.9, diameter 5 mm.; length of carina 10.4 mm.; 

 length of the base of the capitulum 4.9 mm. 



