^L. cordiformis.^ About one inch by one and a half inches thick; reddish in color; resembles a little porcupine. Found on the southern California coast. (Plate LVIII.) GENUS ^Schizaster^ ^S. fragilis.^ One and a half by two inches in size, and one inch thick; color brownish. Lives in deep water off the eastern coast. GENUS =Metalia= ^M. pectoralis.^ A very large heart-urchin, found on the southern coast of Florida and in the West Indies in shallow water. It is, perhaps, the largest species found, being six to eight inches long and proportionately wide and thick. The shell is thin, more or less elliptical, and densely clothed with long reddish-gray spines. (Plate LVIII.) GENUS ^Brissopsis^ ^B. lyrifera.^ A beautiful deep-water species, found off the coasts of Florida and the Gulf of Mexico. It has a red body with pale-yellowish spines. In size it is about two by two and a half inches, and is thickest on the posterior end. It is thickly clothed with long curved spines, some of which form two long tufts in the back. [pg228] TABLE SHOWING THE CLASSIFICATION OF THE HOLOTHUROIDEA DESCRIBED IN THIS CHAPTER Class =HOLOTHUROIDEA= Order =ELASIPODA= (/Deep-sea forms; tube-feet in zones near together/) Order =PEDATA= (/Well-developed tube-feet and false ambulacra/) Genera Species ^Thyone^ ^T. briareus^ ^Pentacta^ ^P. frondosa^ ^Lophothuria^ ^L. fabricii^ Order =APODA= (/Without radial canals, tube-feet, or respiratory trees/) ^Synapta^ ^S. tenuis^ ^S. roseola^ ^S. rotifera^ ^Caudina^ ^C. arenata^ [pg229] CLASS =HOLOTHUROIDEA= SEA-CUCUMBERS