Zoological Society, 73 



son of more specimens from America than he had yet been able to 

 obtain for the purpose of examination. 



The Cross-bill of North America Mr. Gould showed to be very 

 distinct from that of Europe, the Loxia curvirostra, Linn. ; it is 

 one third less in all its proportions, and is somewhat less brilliant in 

 colouring. The Ring Dottrel of North America is also specifically 

 distinct from that of Europe, the Charadrius Hiaticula, Linn. ; in- 

 dependently of differences in admeasurement, its semipalmated foot 

 will always serve to distinguish it. 



In addition to the Birds that have been already mentioned, Mr. 

 Folliott's collection contained a series of the Sylviadce of the United 

 States, several Fly-catchers, the Orphea rufa, &c, &c. 



Mr. Gray exhibited specimens of the shelly covering of a Radiated 

 animal, allied to the Echinidce and the Asteriida, which he regarded 

 as the type of a new genus, and for which he proposed the name 

 of 



Ganymeda. 



Corpus hemisphaericum, depressum ; depressione dorsi centrali 

 quadrangulari. 



Os inferum, centrale. 



Anus nullus. 



Ambulacra nulla. 



"The body is hemispherical, depressed, thin, chalky and hollow. 



" The back is rounded, rather depressed, flattened behind, with a 

 rather sunk quadrangular central space. 



" The sides are covered with sunken angular cavities with a small 

 round ring, having an oblong transverse subcentral hole in their 

 base. 



" The under side is small, rather concave, with five slight sloping 

 elevations from the angles of the mouth to the angles of the rather 

 pentagonal margin. The edge is simple. 



" The mouth is central. The vent none. 



" The cavity is simple. 



" The parietes are thin and minutely dotted, and the centre of 

 the dorsal disc is pellucid. 



" This genus is very nearly allied to the fossil described by Dr. 

 Goldfuss in his beautiful work on Petrifactions, under the name of 

 Glenotremites paradoxus (tab. 49. f. 9. and t.51. f. 1.), with which it 

 agrees in external appearance and form, in the possession of 

 a sunken space on its upper surface, and in having only a single in- 

 ferior pentagonal mouth. It differs from Glenotremites by being un- 

 furnished with ambidacra running from the angle of the mouth to 

 the margin, by being unprovided with conical cavities between those 

 near the mouth, and by having in the flattened disc on the back a 

 central quadrangular impression instead of the pentagonal star of 

 that genus. 



" Dr. Goldfuss describes the glenoid cavities on the surface as 

 giving attachment to spines similar to those of the Turban Echini, 

 (Cidaris, Lam.), and states that the under surface is covered with very 

 small tubercles to which he believes spines were attached. The 



third Series. Vol. 5. No. 25. July 1834. L 



