1886.] NATURAL SCIENCES OF PHILADELPHIA. 165 



flat, the radials extremely large, touching with their acute lower 

 angles the underbasals, thereby almost isolating the five basals. 

 The basals in these species consist of minute trigonal pieces of 

 irregular form, and also the underbasals are small, and rest 

 deeply within the columnar concavity (PL 6, fig. 9). In the 

 earlier form, notably " Zeacrinus " elegans, however, the basal 

 cup is bowl-shaped, and the basals are comparatively larger. The 

 arrangement of the azygous pieces upon which DeKoninck 

 placed so much stress in defining Woodocri7ius, \s, in our opinion, 

 not diflerent from that of Poteriocrinus or Scaphiocrinus, only 

 more plates of the ventral sac are exposed to view, owing to the 

 width of the azygous side, and as we see no other distinction 

 between Woodocrinus and our Pachylocrinus, we place the 

 species which we had referred to the latter, including '' Zeacrinus^'' 

 elegans and a few others of the same type, under Woodocrinus^ 

 as this name has priority. Perhaps, if all American species were 

 as distinct as " Zeacrinus " elegans from Woodocrinus macrodac- 

 tylus, it might be possible to make the former the type of a 

 separate group, but as we find all intermediate forms, from 

 infolding arms to spreading arms, and two to five or more bifur- 

 cations, flat, angular and rounded arms, any such separation must 

 be adandoned. 



Fhilocriaus, De Koniuck, from Punjaub, India, is probably, to 

 judge from the figure, a species of Woodocinnus. We think it has 

 azygous plates, but these were covered by matrix in DeKoninck's 

 specimen. We also doubt if the arm plates of first and second 

 order were laterall}' connected b}^ suture ; these evidently were 

 free as in the Fistulata generally. 



Revised Diagnosis. Calyx sometimes obconical, more fre- 

 quently depressed-bowl-shaped, and the underbasals bent inward, 

 forming a concavity. Basals large, constituting a continuous 

 ring beneath the radials. Az3^gous plates arranged as in Poterio- 

 ciHnus ; ventral sac slightly inflated. Brachials composed of one 

 or two pieces, which jointly have the form and size of the radials ; 

 they are wider than long, and their lateral margins are fitted 

 closely together as if they were united by suture. This infolding 

 of the brachials extends also to the arm plates up to the second 

 bifurcation; and is often found throughout the full length of the 

 arms. The arm joints are short, quadrangular, rarely cuneate, 



