IvCHINOIDEA. I. 8l 



2. The tube feet on the actinal side in a single, ahnost regular 

 series; the test very soft 3. 



The tube feet on the actinal side in tliree more or 

 less separated series 5. 



3. Ophicephalous pedicellarise are found Troniikosoma Koehleri Mrtsn. 



Only tridentate and triphyllous pedicellariie 4. 



4. The tridentate pedicellariae simply leaf-shaped Ecltinosoma uraniis (Wy v. Thomson). 



The tridentate pedicellarise with much involuted blade, 

 the point widened in a spoon-like manner with straight, 

 fineh- serrate edge Hygrosoma Petersii (A, Agass.). 



5. The three series of tube feet rather close together; the 

 ambulacral areas of the common structure; the tridentate 

 pedicellarise not simply leaf-shaped. The hoof small 6. 



The three series of tube feet widely separated; the 

 ambulacral areas on the actinal side formed by 8 series of 

 plates. Tridentate pedicellarias simply leaf-shaped, the 

 largest ones with a rich, thorny net of meshes filling the 

 blade. The hoof large Spcrosoiiia Grimaldii Koehler. 



6. The large tridentate pedicellarise with much involuted 

 edge; the widened part of the point finely, but irregularly 

 serrate in the edge; the smaller tridentate pedicellarise of 



a similar structure Calvcria hystrix Wyv. Thomson. 



The large tridentate pedicellarise with much involuted 

 edge; the widened part of the point is deeply and coarsely 

 indented in the edge. Tetradactylous pedicellarise may be 

 found 7. 



7. The smaller pedicellarias with the widened part of the 



point coarsely sinuate in the edge ArcBOSoma /enestrahim Wyv. Thomson. 



The smaller pedicellarise with the widened part of the 

 point of the blade straight and finely serrate in the edge. 

 Moreover a very large form is found with coarsely in- 

 dented edo-e • ArcBOSoma Belli Mrtsn. 



Fam. Temnopleuridae. 



Hypsiechinus n. g. 



The test generally without distinct grooves or furrows; no distinct slits in the edge of the 

 mouth. The buccal membrane covered with large plates; all the buccal tube feet are generally well 

 developed in the adult individuals. None of the ocular plates reaches quite to the periproct, which is 



The Iiigolf-Expedition. IV. i. H 



