88 



is a slight swelling, commencing at the margin, in the azygous 

 area and extending beyond the azygous orifice, that is covered 

 with very small plates. 



This is a marked and peculiar species, that cannot be mistaken 

 for any hitherto described. 



Found by Mrs. J. M. Milligan, of Jacksonville, Illinois, in 

 whose honor we have proposed the specific name, in the Niagara 

 Group, of Decatur county, Tennessee, and now in her collection. 



FAMILY EUCALYPTOCEINID^E. 



EUCALYPTOCRINUS MILLIGAN^, n. sp. 



Plate V, Fig. 4, basal view; Fig. 5, side view showing the con- 

 striction of the calyx; Fig. 6, side view of another specimen 

 showing the sutures separating the interradials from 

 the summit plates and constriction of the latter 

 above the arms, the azygous orifice 

 being at the top. 



Species medium size. Calyx subturbinate, broadly constricted, 

 in the middle part, and truncated at the base, Surface smooth or 

 granular, our specimens being silicified the granules, if they ever 

 existed, are destroyed. Column small and round. 



Basals within the calyx and with the inferior part of the first 

 radials form a pentagonal, funnel-shaped cavity for the reception 

 of and attachment of the column. First radials wider than long, 

 abruptly curved into the basal concavity, and upward, on the 

 outside, so as to form a sharp, pentagonal rim at the base of the 

 calyx. Second radials quadrangular, less than one-half wider than 

 long. Third radials somewhat larger than the second, heptagonal, 

 and support on each upper lateral side, two secondary radials, 

 the last being axillary and supporting, upon its nearly transverse 

 upper face, two arms. Above three or four transverse plates, the 

 arms are composed of a double series of interlocking plates, as in 

 oth^r species. The outline of each arm, however, is more fusiform 

 than usual. 



The superior point of each third primary radial is truncated by 

 a pair of elongated interbrachials as in the regular inter- 

 brachial areas, and these are followed by a long plate that is di- 



