259 



Ling'ula Gracjana, Rathhun, sp. nov., fig. 2. 



In the only specimen of this species yet obtained, the test is small and elon- 

 gate, the greatest width, which is just behind the middle, being 

 equal to about one-half the length. The outline is elliptical, the 

 lateral margins being very slightly straightened and inclined 

 L. Gracana* towards the front ; beak indistinct ; surface, where preserved, 

 marked with numerous, exceedingly minute, closely arranged, 

 concentric lines, together with a few, coarse growth-lines, imperfectly pre- 

 served in the specimen. The valve is very flat, but this may be the result of 

 pressure. Length 6.5 m. m., width 3.5 m.m. 



This species, which somewhat resembles in form certain varieties 

 of L. mytiloides, Sow., of the Carboniferous of England, occurs with 

 Discina lodensis in the dark shale of the Devonian, near the Iga- 

 rape de Erere, Province of Para, Brazil. (Morgan Expedition 1870.) 



Named in honor of His Excellency, Dr. Abel Gra§a, President of 

 the Province of Erere in 1870 and '71, to whom Prof. Hartt is indebted 

 for the use of the steamer Jurupensem on his Expedition of 1870. 



Lin^ula Stauntoiiiaua; Rathhun, sp. nov., fig. 3. 



This species is represented by a very perfect, though probably flattened im- 

 pression of a single valve ; but, notwithstanding that it preserves 

 faint indications of muscular markings, I have not been able to 

 determine whether the valve is ventral or dorsal. The valve is 



small, a little longer than broad, the greatest width being at about 

 L. Sfavnto- ^ ' & & 



niana. one-fourth the length from the front. In its posterior three quar- 

 ters it narrows backward, the margin being regularly elliptical in outline, and 

 consequently bluntly rounded behind, without a distinct beak. In the anterior 

 fourth of the valve the margin, nearly straight in front, curves rather ab- 

 ruptly round on each side to meet the latei'al margins, so that the general 

 outline of the valve is an oval, slightly flattened in front. The V-shaped line, 

 shown in fig. 3, appears to represent the anterior limits of the muscular im- 

 pressions. Length 8.5 m. m., breadth 6.5 m. m. 



This species occurs associated with Discina lodensis in the dark 

 shale near the Igarape de Erere, Province do Para, Brazil. (Morgan 

 Expedition 1871.) 



Dedicated to Mr. Phineas Staunton, a member of the Expedition 

 of 1870. 



* I have given only an outline drawing of this species of Lingula, since it is impossible to 

 represent accurately its surface markings in a wood cut. 



