PLATE XX. 



FIG. 



1. — A five-sided Steiihanastrum, with a remarkable resemblance in 

 shape to a Cushion-star (Goniaster), being raised in the centre 

 gradually from the edges. Measures from angle to angle .0148, 

 from Chimborazo, Barbados. Dr. Davy. 



2. — A Haliomma, which Dr. Wallieh says "started in life with the 

 intention of being two spiued," met with obstructions, and sub- 

 sided into this form. 



3.— A three-limbed Astromma. — ^For this specimen I am indebted to 

 Dr. Greville. Atlantic Ocean soimdings, 2360 fathoms deep. 

 Lat. 45.41 north: Long. 16.29 west. 



4. — Curious appearance of a twin or double-bodied Polycystiu. 



5. — Rhabdolithes of Ehrenberg, with the pipe stem curved into a circle, 

 and spined. 



0. — A beautiful lamp-shaped Podocyrtis, or possibly a variety of 

 Rhopalocauium of Ehrenberg, not fully developed. 



