242 



internal growth, while the whole interior of the hcuk was filled up. 

 The surface of the mould is smooth, and docs not enable us to 

 decide whether the test was ornamented or plain. 



The single specimen measures as follows: length about 25 

 m. m., breadth about 3-4 m. m., height about 7 m. m. 



From the Devonian sandstone of Erere, found with ^S*. Pcdroana 

 and S. Elizae. (Morgan Expedition 1871.) 



[I have named this species in honor of Capitao Valente, of Monte- 

 Alegre, a gentleman to whom I am under the deepest obligations 

 for hospitality, and for most important aid rendered me in my 

 explorations of the Erere-Monte-Alegre district. — C. F. II.] 



Cyrtina 'I Curupii'a, RatJibun, sp. nov., Plate X, fi^s. 1 and G. 



Ventral valve unknown. Dorsal valve small, moderately or very convex, 

 and most elevated just behind the middle, transverse, sub-semicircular in out- 

 line, with the breadth nearly or quite twice the length, and apparently great- 

 est along the straight hinge line ; but the cardinal extremities in all the 

 specimens are defective, making it impossible to determine whether they are 

 angular or slightly rounded. The sides curve moderately, and the anterior 

 margin is nearly straight in front of the fold. From the front, along the 

 median line, the valve rises more or less rapidly, with quite a strong 

 curvature, for two-thirds or three-fourths its length, and then descends in an 

 abrupt curve to the hinge line, there being no apparent beak. Median fold 

 moderately elevated above the surface of the valve, broad, and composed of 

 three plications, of which the two outer ones are very prominent and regu- 

 larly rounded, the median one being broader but not so high, and slightly 

 flattened along the top. The fold commences near the hinge line, where it is 

 moderately broad, increasing gradually in width towards the front, but seldom 

 gaining much in height. The aides of the valve slope off more or less 

 abruptly towards the cardinal angles, which are broadly flattened. On each 

 side there are generally three rounded plications, not so large as those on the 

 fold, and sometimes much depressed ; they are usually narrower than the 

 reverse plications, and increase gradually in width towards the margins, 

 diminishing, however, in size towards the cardinal angles, which last are 

 smooth. 



At first sight, the specimens on which the above species is founded, 

 might be taken for dorsal valves of Vitulina pustulosa, with Avhich 

 species it is associated in the Devonian sandstone at Erere ; but, as the 

 above description shows, it is very different. Without the ventral 



