140 EXPLOBINti EXPEDITION FROM SANTA FK 



face leads me tosuspecl that it may possibly be a Spirtferina; but as I have not been 

 able to see any certain indications of punctures, I hardly feel warranted in referring it 

 to that group. I have not, however, given' it an examination by the aid of higher 

 power than a strong hand-magnifier; Should a more thorough examination reveal the 

 usual punctate structure, and the internal septum of that group, it will of course have 

 to be called Spir'iferina Texana. 



Compared with foreign forms, this shell seems to be most nearly like the extremely 

 narrow and elongated variety of 8. duplicatus, Phillips, as illustrated by Mr. Davidson's 

 figure 8, Plate IV, Monogr. British Carboniferous Braohiopoda. It is much more 

 gibbous, however, with decidedly more prominent and more angular mesial sinus; 

 while its surface-granulations and minute stria' serve to distinguish it. Although its 

 mesial fold has a very angular appearance, a careful examination shows it to be very 

 slightly flattened, or sometimes even marked by a linear furrow along its crest; and 

 there is sometimes also a slightly more prominent line along the middle of the angular 

 sinus of the other valve. 



Locality and position.— The type-specimen was found, by .Mr. H. R. Roessler, asso- 

 ciated with Coal-Measure fossils in Young County, Texas. Dr. Newberry also has 

 specimens from the northwest corner of Jack County, west fork of Trinity River, Texas. 

 I have never seen it from any locality north or east of Texas. — (R 1>. M.) 



Productus nodosus, Newb. 



Plate III, fitf-s. 3-3 d. 



This tine Productus, first collected on a former expedition, and described in my 

 report to Lieutenant Ives (Colorado Expedition, Ceology, p. 121, plate 1, figs. 7- 

 7 /;), we found in large numbers at Santa Fc, and in many localities along our route 

 quite to the Colorado. Indeed, it is perhaps as common as any other species of the 

 genus in Western Xew Mexico and Southern Utah. 



The figures now given of it will convey a much better impression of its true char- 

 acter than those before published. From these it will be seen that, with a near 

 approach in form and markings to V. com and P. aqukostatus, it is distinguished from 

 these and other species by the single line of conspicuous nodes, the bases of large 

 spines, which mark the median line of the ventral valve. In some specimens a corre- 

 sponding line of tubercles marks the dorsal valve; but they are always less distinctly 

 marked and are often entirely wanting. 



Figures 3 c and 3 d show a somewhat remarkable variation in the length of the 

 cardinal border, but the wings are usually quite short, as in figures 3 b and 3 c. 



Pleii?otoma.ria excelsa, Xewb. 



Plate III, tigs. 4, 4". 



Shell large, long-conical in outline, higher than broad; whorls flattened out- 

 wardly above and below, having an angular section, the lower ones projecting consid- 

 erably beyond the upper, giving the sheila shouldered appearance; surface smooth, 

 or marked with fine lines of growth. Height, 3.2 inches. Breadth, 2.6 inches. In its 



