Miscellaneous. 1 63 



He sums up his conclusions thus : — 



" Nous connaissons actuellement tous les caracteres exte'rieurs des 

 Te're'dines. Une coquille de Taret, portant l'ecusson d'une Pholade, 

 est constamment soudce a l'extremite d'un tube analogue a celui du 

 Taret, mais dont l'extremite est plus semblable a celle des Gastro- 

 chenes," p. 122. 



After reading M. Deshayes's observations with care, I am still of 

 opinion that the real explanation of the genus is, that the tube 

 of the Teredina has no affinity with the tubular sheath of the Teredo, 

 as M. Deshayes continues to believe, and that it is only the fleshy 

 siphons of the animal which have been lined with shelly matter by 

 the process of fossilization ; and I think this fact is further proved 

 by the manner in which the cavity of the shell is lined with calca- 

 reous laminae like the siphons, as figured in M. Deshayes's plate, 

 tab. 4. f. 8, 9, and also by the form of the end of the tube figured 

 in the same work, tab. 3. f. 17, 18. 



On the Variation of the Form of the Upper Mandible in a Rapacious 

 Bird. By Philip Lutley Sclater, M.A. 



Mr. J. H. Gurney has called my attention to the great variation 

 in the form of the upper mandible of TJrubitinga unicincta, as ob- 

 servable in some specimens which form part of his collection. I 

 have seen the same sort of thing in the case of other Accipitres, 

 but never carried to such an extent as in the present instance. In 

 one of these birds (fig. 1 ) the lateral margins of the upper man- 

 dible are strongly festooned, and project far down over the edges 

 of the lower. In a second specimen (fig. 2) — apparently of about 



Fig. 1. Fig. 2. 



the same age, both being in immature plumage — the commissure is 

 very nearly straight. In other examples there is merely a slight 

 festoon. As the formation of the edges of the upper mandible is 

 much in use as a generic character — rightly enough, I believe, and 

 not generally liable to lead to error — the present abnormal variation 

 seems worthy of notice. — Proc. Zool. Soc. March 23, 1858. 



