330 MANUAL OF NATURAL HISTORY. 



terior half of dilated portion furnished with 

 ten ambulacra. 



II. SUB-OBDEB.— Pedate-Holothurians (Pedata.) 



Body furnished with suckers variously arranged. 



3. Family. — Sea-Cactuses (Thyonidse). Body pyri- 

 form when at rest, cylindrical when extended, 

 contractile ; covered all round with numerous 

 papillose suckers ; tentacles ten, branching. 



4 Family. — Sea-Melons (Pentactidas). Body more 

 or less angular or cylindrical; suckers ar- 

 ranged in five longitudinal rows ; tentacles 

 pinnate or ramose. 



5. Family. — Holothurians-proper (Holothuriidse). 



Body cylindrical or flattened horizontally, 

 cartilaginous or gelatinous ; mouth somewhat 

 inferior ; suckers principally over inferior 

 surface, irregularly scattered, a few on the 

 dorsal surface ; tentacles mostly twenty, 

 short, peltate. 



6. Family. — Trepangs (Trepangidse). Body cylin- 



drical or sub-cylindrical, soft, gelatinous, 

 with numerous papillae on back ; mouth an- 

 terior ; suckers placed on inferior surface ; 

 tentacles 6 — 8 ? peltate. 



7. Family. — Scaly -Holothurians (Cuvieriidae). Body 



convex superiorly, sometimes with bony 

 plates ; inferior surface soft, flat, with nu- 

 merous suckers; oral opening tentacular, 

 stellate. 



8. Family. — Sea-Cucumbers (Psolidae). Body ir- 



