On Fossil Echinodenns from /he Island of Malta. 101 



two on each side, long, narrow, deeply plaited, passing from the 

 umbo forwards, uniting behind the byssus and below the adductor, 

 closing the branchial chamber ; outer gill hnear, composed of a 

 single lamina; inner gill thick, strongly furrowed along the free 

 edge. Palpi small, very narrow, pointed, free, 



Cypricardia rostrata, Lam. From the Philippines. 



Mantle-lohes united and covered (except the siphonal area) 

 with a wrinkled straw-coloured epidermis. Siphonal orifices 

 unequal, anal smallest, fringed. Pedal opening (/) rather large. 

 Foot very small, compressed, byssi- 

 ferous. Gills long, narrow, deeply 

 lamellated, very unequal ; outer gill 

 rather shorter, and only lialf as wide 

 as the inner, furnished with a narrow 

 plicated dorsal border ; its lower mar- 

 gin free posteriorly, adhering to the inner gill in front ; inner 

 gill prolonged between the palpi. Palpi small, triangular, 

 plaited inside. Adductor muscles each of two distinct elements ; 

 Knitviov pedal muscle distinct ; posterior combined with adductor. 



Cypricardia ? solenoides, Eeeve. 



Mantle-lohes united, margins slightly cirrated behind. Pedal 

 orifice rather large. Foot very small, compressed, acute-edged, 

 with a large byssal pore near the heel. Siphons conical, cirrated 

 externally ; orifices cirrated ; anal smallest, with a single row of 

 large cirri ; branchial with an inner series of large cirri, and very 

 numerous fine cirri outside. Palpi moderate, obtuse. Gills two 

 on each side, deeply plaited, the ridges grooved ; outer gill sliorter 

 and narrower ; inner gill prolonged between the palpi ; gills 

 united posteriorly, their lower margins entirely free. 



XII. — On Fossil Echinodenns from the Island of Malta ; ivith 

 Notes on the stratigraphical distribution of the Fossil Organ- 

 isms in the Maltese beds^. By Thomas Wright, M.D. &c.. 

 Professor of the Natural Sciences in the Cheltenham Grammar 

 School, 



[With four Plates.] 



A. Azotes on the Maltese beds, with the species they contain. 



The Island of Malta is entirely composed of tertiary rocks of 

 Miocene age, which have been described by Capt, Spratt, Il,N.t, 



* Being the substance of a Lectiu-e delivered to the Members of the 

 Cotteswokl Club, held at Tortworth Court, September 14, 1854. 



t " On the Geology of the Maltese Islands," with Notes on the Fossils 

 by Prof. E. Forbes. Proceed, of the Geol. Soc. London, vol. iv. p. 225. 



