810 PROCEEDINGS OF THE NATIONAL ML'SEf'M. VOL.XX. 



CARDIOMYA GLYPTA Bush. 



(Plat<>s LXXI, fig. 1; LXXYI, figs. 3, 7.) 



Netera costata BUSH, Trans. Conn. Acad., VI, p. 472, pi. XJ,Y, fig. 21, 1885; Expl. 



Albatross, Report U. S. Com. Fish ami Fisheries for 1883, p. 587, 1885; not 



Sowerby, 1834. 

 Cardiomya ornatissima DALL, Bull. Mus. Comp. Zool., XII, p. 296, 1886; Bull. U. S. 



Nat. Mus., No. 37, p. 66, pi. XLI, fig. 21. 1889. 



A few specimens were found at two stations off Cape Hatteras, North 

 Carolina, in 48 fathoms. South to Guadaloupe, in 2 to 124 fathoms. 

 Ball. 



In addition to the published description it should be stated that the 

 antero-dorsal margin of the right valve rises into a distinct, prominent, 

 obtuse lobe in front of the tooth; this lobe overlaps the margin of the 

 left valve when the shell is closed. There is a small buttress beneath 

 the posterior lateral tooth. One broken valve, considerably larger than 

 the type, has in the intervals between the three primary ribs two or 

 three small secondary ones; on the anterior end six ribs are visible, of 

 which one or two are larger than the rest, so that altogether about thir- 

 teen or fourteen ribs can be counted; some of these are, however, very 

 small and extend only part way to the urn bo; even the largest do not 

 extend over the extreme part of the umbo. 



Mr. Dall considers this species to be identical with D'Orbigny's orna- 

 tissima, but we see no sufficient reason for uniting the two forms. 



The name costata was used by Sowerby in 1834. 



HALONYMPHA STRIATELLA, new species. 

 (Plates LXXII, figs. 2, 3; LXXVII, fig. 10.) 



Shell small, thin, broadly and obliquely ovate, with a narrow, short 

 rostrum. Unibo swollen. Beak behind the middle. The antero-dorsal 

 margin is broadly and nearly evenly convex ; the anterior end is evenly 

 rounded; the ventral margin is broadly convex with a slight incurva- 

 ture at the base of the rostrum, which is short, narrow, and obtuse at 

 the end; the postero-dorsal margin is strongly concave and slopes 

 rapidly. In the region of the umbo the surface is lustrous and nearly 

 smooth, but marked with faint, parallel lines; elsewhere it is closely 

 covered with very regular, fine, raised concentric lines separated by 

 incised lines of about the same width or narrower; on the rostrum 

 there is a faint diagonal ridge posterior to which the concentric lines 

 are irregular. The interior surface is smooth and lustrous but the 

 external lines show through by transparency. In the right valve there 

 is a small, sharp, triangular tooth projecting inward with a very small 

 cartilage-pit in front of and confluent with it; slightly farther forward 

 there is another small, slender tooth rising nearly parallel with the 



