DESCRIPTIONS OF NEW SPECIES. 107 



277. Dentalium f. Bijou Basin, Colorado. Much like No. 276, 



except that its surface is marked only by encircling lines of growth. 



278. Melania Larunda White. Crow Creek, Colorado, where it is 

 associated with No. 271. Described on a following page. 



279. Patella f. Bijou Basin, Colorado. A single small exam- 

 ple. 



280. Phorus exoneratus White. Bijou Basin, Colorado, forty miles east 

 of Denver, Colorado. Described on a following page. 



281. Cerithium f. Bijou Basin, Colorado. A single, small, 



imperfect example. 



t 



DESCRIPTIONS OF NEW SPECIES OF INVERTEBRATE FOS- 

 SILS FROM STRATA OF THE CARBONIFEROUS, JURASSIC, 

 CRETACEOUS, AND TERTIARY PERIODS. 



CARBONIFEROUS PEKIOD. 

 Radiata. 

 Actinozoa. 



Genus AMPLEXUS Sowerby. 



Amplexus zaphrentiformis (sp. nov.). Corallum having the external aspect 

 of Zaplirentis rather than of Amplexus, being elongate-conical in form, more 

 or less curved and tapering to a point or small pedicil at the base; epitheca 

 well developed, having its surface marked by the usual concentric wrinkles 

 and lines of growth, and with longitudinal lines marking the position of the 

 septa, the latter not being very distinct; calyx circular or subcircular, the 

 plain portion of the surface at its bottom equal to one-third or more of the 

 diameter of the corallum ; septal fossette well developed, situated at the con- 

 cave side of the corallum; septa thirty or forty in number, rather strong; 

 transverse plates numerous, well developed, somewhat irregular, and ending 

 exteriorly against a moderately well developed external wall, which is dis- 

 tinct from the epitheca proper. This external wall contains no vesicles and 

 apparently consists of solid coralline substance. 



