PLATE XX.
1. A five- sided Stephanastrum, with a remarkable resemblance in shape to a Cushionstar (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. Wallich says "started in life with the intention of being two spined," met with obstructions, and subsided into this form.
3. A three-limbed Astromma. -For this specimen I am indebted to Dr. Greville . Atlantic Ocean soundings, 2360 fathoms deep . Lat. 45.41 north ; Long. 16.29 west.
4. Curious appearance of a twin or double- bodied Polycystin.
5. Rhabdolithes of Ehrenburg, with the pipe-stem curved into a circle, and spined.
6. A beautiful lamp-shaped Podocyrtis, or possibly a variety of Rhopalocanium of Ehrenberg, not fully developed.
