22 BULLETIN 100, UNITED STATES NATIONAL MUSEUM 



AMPHORA DURA, new species 



Plate 4, fig. 2 



Dorsal side with a sharp median indentation in which is a single 

 large bead, the dorsal edge being barely convex to within one-sixth 

 of the ends, then curved smoothly down to the ventral edge; ventral 

 side slightly biconcave; rhaphe starting from a strong central nodule, 

 arched upward on both sides and terminating in two large spherical 

 nodules set at the sharp apices of the ends on the central side; an 

 indistinct hyaline stauros across the valve from the dorsal bead to 

 the central nodule; closely set coarse vermiform markings over the 

 entire valve. 



Length, 0.124; width, 0.023 mm.; no transverse lines. 



Although this form is near A. obtusa Gregory, the massive bead on 

 the dorsal side and the constant vermiform markings give it more 

 than varietal rank. It is related to A. delphinia Bailey, as figured in 

 Schmidt's Atlas, plate 40, figures 24-27. It is abundant in all Phil- 

 ippine Islands gatherings and is uniform in appearance. 



Type.— Cat. No. 43574, U.S.N.M. 



AMPHORA EGREGIA Ehrenberg 



(Schmidt, Atlas, pi. 28, figs. 13-15.) 



All my specimens are of the Campeche Bay variety, as mentioned 

 in the above reference. 



AMPHORA EXSECTA Grunow 



(Janisch, Gaz. Exp., pi. 21, fig. 2; Schmidt, Atlas, pi. 27, fig. 55, not fig. 54.) 



AMPHORA FLEXA, new species 



Plate 4, fig. 4 



Dorsal side of the valve smoothly bent at the middle, barely con- 

 vex to the narrow ends; ventral side even less strongly concave; ends 

 small, evenly rounded; rhaphe close to the ventral edge, slightly 

 double-bowed; a large hyaline central area extending across the 

 valve from the central nodule on the ventral edge to near the dorsal 

 side, where there are short rows of beads; markings of loosely set 

 rows of beads radially arranged, parallel, with interspaces as wide as 

 the rows, none transverse. 



Length 0.118; width 0.024; lines 8 in 0.01 mm., measured on the 

 dorsal side. 



It bears a slight resemblance to A. scabriuscula Cleve and Grove 

 (Le Diat., vol. 2, pi. 3, fig. 7). A variety occurs with the beads 

 somewhat unevenly placed in the different rows, thereby giving a 

 wavy appearance to the marking. 



Type.— Cat. No. 43575, U.S.N.M. 



