18 



AVICULA UN'DOSA (N. Sp.). PI. 2, fig. 9. 



Shell almost flat, oblique, very thin; anterior alation rather 

 small, terminating in an acute point; posterior alation broad, 

 curved backwards along the hinge line into an acute point; 

 body of shell long. Surface, except alations, marked by well 

 defined, rather broad, flat, radiate plications, inter-plicate spaces 

 shallow and about as wide as the plication; plications grow 

 broader as they approach the margin and increase by inter-pli- 

 cation and bifurcation. Entire surface crossed by laminate 

 stride which are undulose where they cross the plications. 



This species usually measures over two inches in its longest 

 diameter; the smallest specimen in my collection measuring 

 one and three-fourths, and the largest two and one-half inches. 



CONULARIA MULTIPUNCTA (N. Sp.). PL 2, fig. 10. 



Shell exceedingly thin, epidermic in character; very fragile, 

 angles apparently quite sharp. Surface having a narrow, flat, 

 barely elevated plication passing down the center of each side, 

 tapering slightly towards the apex. Transverse ridges very 

 fine, and have a rounding, downward curve from the sharp, 

 linear sulcations at the angles; there are about twenty-five to 

 one-eighth of an inch. 



Only the interior of the shell is known, but judging from the 

 microscopic, crowded punctures the ridges must be ornamented 

 by a multitude of closely crowded nodes or points, of which 

 there are thirty to one-eighth of an inch. Surface between the 

 transverse ridges apparently quite smooth. 



CONULARIA BIFURCA (N. Sp.). PI. 2, fig. 11. 



Shell gradually tapering, small. Surface crossed by very 

 fine, smooth, thread-like, transverse ridges; many of which bi- 

 furcate once, and sometimes twice, in crossing from the sulca- 

 tion of one angle to the other; they are bent abruptly down- 

 wards near the angles, and meet at an acute angle in the 

 sulcations; and also have a faint downward curve towards the 

 center of the sides; there are twenty to one-eighth of an inch. 



Surface between ridges smooth. 



