EEPOKT ON THE EADIOLAEIA. 591 



former. Arms club-shaped, their basal semi-cylincbical, half as broad as the spherical distal half, 

 which bears a strong, conical, terminal spine. The discoverer of this remarkable, very old, Liassic 

 species, Dunikowski, supposes that it is not a true Discoid, from the absence of a central disk ; in 

 my opinion the central disk (nearly spherical) has the same relation to the arms as in many other 

 Discoidea, theu- equatorial plane is the same. 



Dimcnsio7is. — Eadius of the odd arm O'lS, of the paired arms 0'24 ; basal breadth 0'08, distal 

 breadth OIG. 



Habitat. — Fossil in the Alpine Lias, Schafberg, near Salzburg, Dunikowski. 



6. Rhopalodictyum elongatum, n. sp. 



Arms of different size and at unequal distances, one odd arm being twice as long as both paired 

 arms ; the odd angle between the latter much larger than both equal pau-ed angles. Arms nearly 

 cylindrical, little flattened, three to six times as long as broad, with rounded blunt distal end. 



Dimensions. — Eadius of the arms 0'15 to 0'3, breadth O'Oo. 



Habitat. — Pacific, central area. Station 274, surface. 



7. Rhopalodictyum curvatum, n. sp. 



Arms of different size and at unequal distances, irregular, more or less curved, nearly cylindrical, 

 five to ten times as long as broad, with rounded blunt distal end. (There were observed only two 

 specimens of this remarkable irregular species ; in one specimen all three arms were simple, in the 

 other one odd arm forked. The length of the arms and the size of the angles between them seems 

 to be very different and variable. 



Dimensions. — Eadius of the arms 0"3 to 0'6 to I'lo, breadth 0'06 to 012. 



Habitat. — Pacific, central area, Station 271, surface. 



Genus 263. Dictyocoryne,^ Ehrenberg, 1860, Monatsber. d. k. preuss. Akad. 



d. AViss. Berlin, p. 830. 



Definition. — Sp ong o discida with three spongy arms on the margin of the 

 circular or triangular disk, connected by a spongy patagium of different texture. 



The genus Dictyocoryne differs from the foregoing Rhopalodictyum only in the 

 patagium, connecting the three spongy arms, and bears to it the same relation as in 

 the Porodiscida Euchitonia does to Rhopjcdastrum. The typical species of this 

 genus is Dictyocoryne profunda, the only species figured by Ehrenberg. After his 



' Dictyocoryne = ^et with clubs ; oiktuov, xo^mh. 



