298 L. Agassiz on the Echinodermata. 



are however not yet well enough based to be admitted without re- 

 serve. Several of them I have not had occasion to examine myself. 



1. Synapta, Esch. {Fistularia, De Bl. — Tiedemannia, Leuck. — 

 Holothuria, De Bl. sect. D.) — Body vermiform, presenting no differ- 

 ence between the upper and under surface ; epidermis delicate ; the 

 mouth surrounded by large pinnatifid tentacula. Tubercles, for the 

 most part crooked, and serve as feet, although the animal is not en- 

 tirely destitute of vascular tubes. 



S. Beselii, Jaeg. — S. oceanica, Less. — S. mammillosa, Esch. — 5. vittata, 

 Jgeg. — (Tiedemannia vitt., Leuck.) — S. reciprocans, Jseg. — (Fistularia, re- 

 cipr., ForsJc. — Holothuria glutinosa, Lam.) — S. maculata, Jaeg. (Hoi. mac., 

 Cham.) — S. radiosa, Jaeg. (Hoi. rad., Regn.) — S. inhcerens, Wieg. (Hoi. inh., 

 Mull) 



2. Chirodota, Esch. — Epidermis thin, rather thicker however 

 than in Synapta, beset with a small number of feet or merely of re- 

 tractile mammillae. Tentacula digitate. 



Ch. purpurea, Less. — Ch. lumbricus, Esch. — Ch. verrucosa, Esch. — Ch. 

 discolor, Esch. 



3. Thyone, Oken. (Mulleria, Flem.) This genus differs from the 

 preceding solely in having the entire body covered with retractile 

 papillae. 



Th. papillosa (H. papill., Mull).—Th. fusus (H. fus., Mull.).—Th. im- 

 patiens (B. imp., Forsk.). — Th. maculata (Hoi. mac, Le S.). — Th. Briareus 

 (Hoi. Br., Le S.).—Th. lapidifera (H. lapid., Le S.).— Th. peruviana (H. 

 peruv., Le S.). 



4. Trepang, Jaeg. — Body subcylindrical; mouth anterior, sur- 

 rounded by ten to twenty tentacula in a peltate head ; feet confined 

 to the belly. This genus is doubtful, and ought probably to be 

 united to the Holothuriae properly so called. 



T. edulis (Hoi. edul., Less.). — T. ananas, Jseg. 



5. Holothuria, Linn. ; DeBl. sect. B. {Fistularia, Lam.) — Body 

 subcylindrical, anus rounded ; mouth subinferior. Retractile tubes 

 developed, especially under the belly. 



H. tubulosa, Linn. — H. columnce, Cuv. — H. maxima, Forsk. — H. elegans, 

 Mull.— H. Forskalii, Delle Ch.— H. Petagnii, Delle Ch.— H. Sanctorii, 

 Delle Ch.— H. Cavolinii, Delle Ch— H. Polii, Delle Ch.— H. Stellati, 

 Delle Ch. — H. Dismarii, Cuv. — H. appendiculata, De Bl. — H. radackensis, 

 Cham. — //. brunnea, Cham. — H. agglutinata, Le S. — H. umbrina, Rupp. et 

 Leuk. — H. quadrangular is, Less. — H.fusco-cinerea, Jseg. — H. atra, Jseg. — 

 H. fusco-punctata, Jseg. — H. lilla, Less. — H. scabra, Jseg. — //. monacaria, 

 Less. 



6. Mulleria, Jaeg. — Back convex ; belly flat ; skin coriaceous ; 

 twenty tentacula peltate and disposed in two series round the mouth ; 



