Encrinus liliiformis (Lily Encrinite). [Lign. 91, fig. 6.]—This exquisite Crinoid is equally interesting and attractive to the amateur collector and the naturalist. Its remains do not occur in the British strata, and are only known in the muschelkalk of Lower Saxony. The specimens in this country are chiefly from Erkerode, in Brunswick; they are found in a layer, about eighteen inches thick, of a soft argillaceous cream-coloured limestone, chiefly made up of trochites, detached ossicula, and a few fragile shells and corals.
The receptacle of the Lily Encrinite is smooth, and in the form of a depressed vase; its base is composed of five plates, upon which are placed three successive series of other plates, with the uppermost of which the arms articulate. The stem is formed of numerous perforated round ossicles, articulated to each other by radiated grooved surfaces, and becoming somewhat pentangular, and alternately larger and smaller, towards the summit, to which the receptacle is fixed; a construction admitting great freedom of motion.[278]
[278] Mr. Miller's work should be consulted for details of structure.
This Encrinite when lying in relief on the rock, with its receptacle entirely or partially closed (see Wond. p. 548), so strikingly resembles the bud or expanding flower of a Lily or Tulip, as to justify the popular name of Stone-lily. An exquisite specimen is figured by Mr. Parkinson;[279] the British Museum possesses some fine examples.[280]
[279] Pict. Atlas, pl. xlviii.
[280] Petrifactions, p. 77.
Mr. Parkinson detected the animal membrane in ossicles of this crinoid, by immersing them in dilute hydrochloric acid.[281] My friend Mr. Frederick Harford has repeated the experiment with success.
[281] See Pict. Atlas, pl. xlvii. fig. 47.
PENTACRINITES.