L. Agassiz on the Echinodermata. 299 



five teeth surrounding the anus, to which are attached the longitu- 

 dinal muscles. In other respects it resembles Holothuria. 

 M. echinites, Jseg. — M. Lecanora, Jseg. 



7. Bohadschia, Jseg. — Differs from the genus Mulleria by the 

 star-like form of the anus. This genus otherwise approaches closely 

 to Holothuria. 



B. marmorata, Jseg. — i?. ocellata, Jseg. — B. Argus, Jseg. — B. lineolata, 

 Jseg. — B. albiguttata, Jseg. 



8. Cuvieria, Peron. — Inferior surface flat and soft, furnished 

 with a great number of feet ; superior surface inflated, supported by 

 bony scales, pierced in front by a starlike orifice, which is the 

 mouth, and from which the tentacula proceed, on the under side by a 

 round aperture, which is the anus. 



C. Squammata (Hoi. Squammata, Mull.). — C. Cuvieri, Jseg. 



9. Psolus, Oken. — Back convex ; belly flat; all the feet situated 

 in the middle of the under part of the body ; tentacula ramified, sim- 

 ple, not peltate. When the animal crawls, it raises its two extre- 

 mities where the head and anus are situated, which are more con- 

 tractile than the middle part, especially the anal extremity. 



Ps. Phantopus (Hoi. Ph., Linn.). — Ps. appcndiculatus (Hoi. appen., De 

 BL). — Ps. Timama (Hoi. Tim., Less.). 



10. Pextacta, Goldf. (Cucumaria, Cuv. et Jseg.) — Body cylin- 

 drical or oval-oblong ; pedicules disposed in five series ; tentacula 

 pinnate or branchy. 



P. crocea (Hoi. croc, Less.). — P. Pentactes (Hoi. Pent., Mull,). — P. 

 Gcertneri (Hoi. Gaert., De Bl.).—P. frondosa (H. frond., Gun.).— P. Do- 

 lolium (H. Dol., Pall.). — P. tentaculata (Hoi. tent., Forst.).- — P.lcevis (Hoi. 

 Isevis, Fair.). — P. minuta (Hoi. min., Fabr.). — P.pellucida (Hoi. pellu- 

 cida, Mull,). 



11. Minyas, Cuv. — Body spheroidal, opened at both extremities, 

 grooved like a melon at the two sides, which extend from the anus 

 to the mouth, and which are formed of solid and corneous papillae ; 



• mouth surrounded by three series of short, vermicular, and rounded 

 tentacula. This genus and the preceding connect the Holothurise 

 with the Echinides. 



M. cyanea, Cuv. (M. ccerulea, Less.) 



II. 



The order of the Echinides is characterized by a solid shell, sphe- 

 roidal, composed of adherent plates, and covered with moveable 

 spines ; all of them have a distinct mouth and anus. I divide them 

 into three natural families, which are the Spatangi, the Clypeastres, 

 and the Cidarites. 



