ECHINODERMATA. 159 
Cuvieria Péron. Body often convex, covered with calcareous 
imbricated scales, plane beneath, beset with numerous feet. 
Psolus squamatus MuELL. Zool. danic. Tab. x. fig. 1—3, Guirin Iconogr. 
Zooph. Pl. 4, fig. 2, &e. 
Orper II. A [poda. 
Body covered with a coriaceous, sometimes soft, skin, destitute 
of ambulacral feet. 
Family V. Synaptine. Body cylindrical, elongate. A cal- 
careous ring around the cesophagus. Mouth crowned with tentacles. 
Most writers unite these animals with the Holothurie. 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 Branpt. Tentacles peltate. Respiratory organs 
arborescent. 
Sp. Liosoma Sitchaense Br. 
Chirodota Escuscu. Tentacles digitate at the extremity. 
(Respiratory organs?) Skin thickish. Body vermiform. 
Sp. Chirodota discolor, Escuscu. Zoologisher Atlas 11. folio, Berlin, 1829, 
p- 12, Tab. x. fig. 2 ; Chirod. verrucosa Escuscu. 2b. 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 Luss., Centur, Zool. Pl. 52, fig. 2, and 
Holothuria digitata Montacu, Linn. Transact. x1. 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 Escuscu., Tiedemannia Leuck. ‘Tentacles pinnatifid. 
No arborescent respiratory organs. Skin very delicate, rough from 
hooklets extremely minute, calcareous. 
EscHscHoutz named this genus (from cuwvdrrw, adnecto), on account of its 
adhering to the skin by means of small hooklets, which he compares to the 
appendages of the calyx of the Burdock (Arctiwm lappa). He found 
Synapta mamillosa on the coast of Otaheiti, Zool. Atl. 1m. Tab. xX. fig. 1. 
To this genus belongs also Holoth. oceanica Luss. Centur. Zool. Pl. 35; Holoth. 
radiosa, ibid. Pl. 15; Pistularia vittata Forsx. Icon. Rer. Nat. Tab, Xxxvit. 
fig. 2, &. 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. Mémoire sur le Synapte 
