PALEONTOLOGlC CONTRIBUTIONS 6/ 



plates nor spinose integument nor dorsal plates. From the geno- 

 type, K . mirabilis, this form is distinguished by its much 

 smaller dimensions, the ray being but one-third as wide and the 

 ambulacral ossicles numbering twice as many (thirty in 10 mm) 

 as in K . m i r a b i 1 i s . 



Lingula semina nov. 

 Plate 24, figures 5 and 6 



Description. Shell small, flat, widest in middle, elongate-ellipti- 

 cal ; one-half times longer than wide ; anterior and posterior extreme 

 ities subequally and acutely rounded ; posterior somewhat more 

 acute than the anterior; lateral margins nearly parallel and but 

 slightly curved. Surface flat; projecting at beak, whence a widen- 

 ing low ridge extends anteriorly and fades out toward the middle. 

 Brachial valve relatively wider and its posterior margin more 

 obtuse. Exfoliated pedicle valves show a broad median longitudi- 

 nal depression (septum or progressive muscle-scar) that extends 

 nearly the full length of the valve; and alongside of this in the 

 posterior region the faint depressions of the progressive lateral 

 muscle-scars (see pi. 24, fig. 5). Shell thin, light colored, phos- 

 phatic-calcareous, with little carbonaceous matter ; surface finely 

 striated. The pedicle valve measures about 9 mm in length and 

 5 mm in width. 



Horizon and locality. Pittsford shale, Pittsford, Monroe 

 county, N. Y. 



Remarks. This pretty little Lingula covers some surfaces of the 

 shale and also of the waterlime bands in wonderful profusion. 

 With its light yellow color and elongate-elliptical shape it greatly 

 resembles melon or cucumber seeds. L . semina resembles 

 L . v i c i n a in outline and size but differs distinctly in being 

 flat and is relatively longer and narrower. Nevertheless the two 

 are similar enough to suggest that the younger might be a derivative 

 or mutation of the earlier Pittsford form, which returned after 

 the uncongenial conditions of the Salina sea had changed. 



Lingula testatrix nov. 

 Plate 24, figures 7 and 8 



Description. Valves of median to small size, of oblong outline, 

 two-thirds as wide as long at the widest place, which is near the 

 anterior margin. The latter straight or but little convex, abruptly 



