LAMELLARIA. 237 



and Sigaretus Siromii of Sars. Fossil in the Coralline 

 Crag at Sutton (S. Wood); Palermo (Philippi). Abroad 

 this species ranges from Norway (Loven and others) to 

 Madeira and the Azores (M^Andrew)^ and throughout 

 the Mediterranean^ Adriatic, and ^gean (Linne, v. 

 Schrockinger, Forbes, and others), the coasts of the 

 United States (Gould and Stimpson), and Canada 

 (D^Urban) ; shore to 69 f. 



The mantle, tentacles, and foot assume different posi- 

 tions when the animal is quiescent and in active motion. 

 It swims or floats with apparent ease. The gill-plume 

 (whether single or double I could not make out) is of 

 a yellowish-brown colour. Mr. Daniel found constantly 

 in the stomach portions of branched corallines, probably 

 indicating that the Lamellaria feeds on Polyzoa. Ac- 

 cording to Mr. Peach the female eats a round hole in a 

 jelly-like compound Ascidian {Leptoclinum punctatum) , 

 for the purpose of making her nest and depositing in it 

 her eggs. This nest is pot-shaped, and covered by a 

 circular lid ; it is at first bright yellow, which after some 

 time fades and changes, becoming at last dirty white. 

 As the embryo increases in size the nest rises up beyond 

 the surface of the Ascidian, having been previously 

 covered on all sides. The spawn is deposited from 

 February to May ; it arrives at maturity in four or five 

 weeks. The embryo, when enclosed and swimming in 

 the glairy matrix, is of a somewhat triangular shape ; the 

 front portion is trilobed, each lobe being furnished with 

 delicate vibratile cilia which are in constant motion; the 

 central portion is granular, and the hinder bluntly 

 pointed. On the pot-lid bursting open, and the fry 

 emerging, the latter is found to have a pellucid nautili- 

 form shell, retaining in other respects the appearance 

 of its foetal state, and destitute of tentacles, eyes, or foot. 



