Messrs. Austins' Arrangement of the Crinoidea. Ill 



by simple or dichotomous rays (not pinnate) furnished with spines, 

 which are used as organs of motion. 



Class 3. Lobistella, Austin's MS. Cirrhigrada, Forbes. 

 Body more or less covered with calcareous scales or plates ; mouth 

 not surrounded by arms ; body lobed and channeled for cirrhi. 



Class 4. Adelostella, Austin's MS. Cirrhi-Spini- 

 grada, Forbes. 



Body covered with closely -jointed calcareous plates, not lobed, 

 and without arms, sometimes furnished with a calcareous flexible 

 jointed column, but most of the class are free. 



Order 1. Echinidce. 

 Animal free, furnished with series of ambulacral pores for the pro- 

 trusion of cirrhi, which, in connection with spines attached by liga- 

 ments to the plated skeleton, constitute the organs of motion. 



Order 2. Columnida, Austin's MS. 

 Animal attached by a jointed flexible calcareous column to extra- 

 neous bodies ; ambulacral pores sometimes wanting, in other instances 

 they are scattered irregularly among the plates ?, but they are usually 

 in regular series, as in the order Echinidce j surface mostly covered 

 with spines, though occasionally smooth. 



Family 1. Sph^ronoide,e, Gray. 

 Genus 1. Sphceronites . 

 Sp. 1. S. tessellatus, De la Beche. Sp. 3. S. pomum. 

 2. S. aurantium. &c. &c. 



Genus 2. Sycocrinites, Austin's MS. 

 Sp. 1. S. clausus, Aust. MS. Sp. 3. S. anapeptamenus, Aust. MS. 



2. S. Jacksoni, Aust. MS. 



Family 2. Echinocrinoidea, Austin's MS. 

 Genus 1. Echinocrinus, Agassiz. 

 Sp. 1 . E. pomum, Agass. Sp. 3. E. anceps, Aust. MS. 



2. E. spinosus, Aust. MS. 4. E. cidariformis 1 Aust. MS. 



Genus 2. Pentremites, Say. 

 Sp. 1. P. inflatus. Sp. 5. P. acutus, Gilb. 



2. P. pyriformis, Say. 6. P. ? astrafornris, Aust. MS. 



3. P. florealis. 7. P. pentangularis. 



4. P. ovalis, Goldf. 



Genus 3. Orbitremites. 

 Sp. 1. O. globosus. Sp.4. O. angulatus? Gilb. 



2. O. Derbiensis, Sow. 5. O. oblongus, Gilb. 



3. O. ellipticus, Sow. 



Class 5. Ascidiastella, Austin's MS. Cirrhi-Vermi- 

 grada, Forbes. 

 The animals of this class deviate considerably from those in the 

 preceding ones. As spines are wanting, motion is effected by rows 



