Mr, Swainson on several new groups in Ormthologt/. 343 



to conduct the water to the branchiae. This genus seems to be 

 the connecting link of those animals which have the aperture of 

 their shells entire, with those that are channeled ; in fact it may 

 be considered as the commencement of the Zoophagi, having 

 shells with a canal at their base (tliough here it is scarcely per- 

 ceptible), and which is continued and becomes more developed ia 

 the Cerilhiada\ It also allbrds a beautiful illustration of the 

 almost imperceptible gradations by which Nature passes from 

 one system of form to another ; for in this genus, the aperture 

 being almost entire shews that it has still something in common 

 with that class of shells it is about to leave, and the evident rudi- 

 ments of a canal connect it with that class it is about to enter. 



The shell of Scalaria Clathratula^ (Turbo Clathratulus,Mont.f) 

 appears very distinct from that of Scalaria Cluthrus or S. commu- 

 nis, but the external organs of the animals inhabiting the three 

 species are alike; the only difference consists in colour, which in 

 the S. ClathrutiUus is quite white, or pale yellowish white, whilst 

 in the two others, it is dark purple or black. 



Art. XXXV. On several Groups and Forms in Ornithology, 

 not hitherto defined. Bj/ William Swainson, Esq., 

 F.R.S., F.L.S., Sfc. 



[Concluded from p. 175.] 



Family Fringillida. 



Sub-familij Alaiidina. 



*Rosfrum forte, siihcylindricum, immarginatum, rectum, narihus 

 plumulis setaceis ohtectis ; rictu sub-barbato. Pedes subfortes ; 

 halluce forti, ungue recto. 



ALAUDA. 



Rostrum breve, subconicum. 



Alee longa ; remigibus \md^ 2dd^ et Stidfere aqualibus, longissimis, 



Cauda sub-furcata. 



