312 PROCEEDINGS OP THE ACADEMY OF [1879. 



subgenerically under Cyathocrinus; if it has but three, as Schultze 

 supposed (they have not been observed), it should be similarly 

 ranked under Gissocrinus, but at all events under the Cyathocri- 

 nidse. 



Generic Diagnosis. General form of the calyx cyathiform; 

 symmetry bilateral. 



TJnderbasals very small, entirely covered by the column, their 

 number not ascertained. Basals five, four of them equal, the fifth 

 or posterior one with the upper side truncate. Radials large, 

 alternating with the basals; articulating faces concave, occupying 

 one-half to two-thirds the width of the plate. Brachials two to 

 four or more, their number varying in the different nays, as well 

 as in different individuals. They are very short, the upper one 

 supporting on each sloping side two main arms, whieh divide on 

 the second or third plate, each division branching several times 

 again. 



Arms long, composed of simple joints, and provided with a dor- 

 sal canal 1 and a deep ambulacral furrow. No pinnulse. 



Anal plate one, constructed as in Cyathocrinus and resting 

 upon the truncate posterior basal. Ventral sac in form of a long 

 tube, constructed of numerous very regular hexagonal plates of 

 equal height, longitudinally arranged in alternately wider and 

 narrower rows. 



The column, which forms the best generic distinction, is obtusely 

 quadrangular, with slightly concave sides, and is composed of very 

 narrow joints of equal size, which are penetrated by a large central 

 and four smaller accessory canals, situated within the joints of the 

 four angles. 



The only known species is : 



*1866. Lecythocrinus briareus Schultze. Echinod. Eifl. Kalk., p. 36, pi. 4, fig. 1 

 (1858. Locythocr. Eifelianus Miiller.) ; 1879. Zittel. Lecythocrinus Eifel- 

 ianus, Mandbuch d. Petrefactenkunde. 3te Liefer. (Now in press.) Devonian, 

 Eifel, Germany. 



8. GISSOCRINUS Angelin. 



1878. Iconog. Crin. Suec, p. 10. 



General form of body including arms elongate, slightly veu- 



1 By " dorsal canal" we understand the longitudinal passage, which oc- 

 curs in some forms through the calcareous joints of the arms, next to the 

 dorsal side, and in connection with the nervous centre in the calyx. 



