ECHINODERMATA. 159 



Cuvieria PERON. Body often convex, covered with calcareous 

 imbricated scales, plane beneath, beset with numerous feet. 



Psohts squamatus MUELL. Zool. danic. Tab. x. fig. 13, GUEKIN Iconogr. 

 Zooph. PL 4, fig. i, &c. 



ORDER II. Apoda. 



Body covered with a coriaceous, sometimes soft, skin, destitute 

 of ambulacral feet. 



Family V. Synaptince. Body cylindrical, elongate. A cal- 

 careous ring around the oesophagus. Mouth crowned with tentacles. 



Most writers unite these animals with the HolotJmrice. But 

 beyond doubt they form a distinct family, of which, however, the 

 structure has been made known to us only in a single genus by the 

 investigations of QUATREFAGES. 



Liosoma BRANDT. Tentacles peltate. Kespiratory organs 

 arborescent. 



Sp. Liosoma Sitchaense BB. 



Chirodota EsCHSCH. Tentacles digitate at the extremity. 

 (Respiratory organs ?) Skin thickish. Body vermiform. 



Sp. Chirodota discolor, ESCHSCH. Zoologisher Atlas II. folio, Berlin, 1829, 

 p. T 2, Tab. x. fig. 2 ; Chirod. verrucosa ESCHSCH. ib. fig. 3, both from the 

 North-west coast of America ; these animals live in the sand and under 

 stones on the shore, in situations which are not quite dry at ebb-tide. 

 Here belongs also Holoth. purpurea LESS., Centur. Zool. PI. 52, fig. 2, and 

 Holothuria digitata MONTAGU, Linn. Transact, xi. Tab. iv. fig. 6. Accord- 

 ing to BRANDT there are situated on the mesentery small cylindrical bodies 

 divided at the extremity, which are subservient to respiration. 



Synapta ESCHSCH., Tiedemannia LEUCK. Tentacles pinnatifid. 

 No arborescent respiratory organs. Skin very delicate, rough from 

 booklets extremely minute, calcareous. 



ESCHSCHOLTZ named this genus (from GVV&TTTU, adnecto], on account of its 

 adhering to the skin by means of small booklets, which he compares to the 

 appendages of the calyx of the Burdock (Arctium lappa). He found 

 Synapta mamillosa on the coast of Otalieili, Zool. Atl. n. Tab. x. fig. i. 

 To this genus belongs also Holoth. oceanica LESS. Centur. Zool. PL 35 ; Holoth. 

 radiosa, ibid. PI. 15 ; Fistularia mttata FOESK. Icon. Her. Nat. Tab. xxxvu. 

 fig. 2, &c. QUATREFAGES discovered a species in the sand at the Chausey 

 Isles, which, in my opinion, has much resemblance to the last-named species 

 of FORSKAL, and gave a detailed description of it. Mcmoire sur k Synapte 



