552 



ON THE ANATOMY OF SCOPUS UMBKETTA. [NoV. 18, 



families by the presence or absence of the ambiens ; and the fact 

 that Scopus umbretta has not the ambiens, but has the semitendinosus, 

 its accessory, and the femoro-caudal, is no clear indication of its 

 affinities with either. In the condition of \\\& pectoral muscle, 

 however, Scopus decidedly agrees with the Ardeidse and differs from 

 the Ciconiidse. 



The disposition of the deep plantar tendons is not characteristi- 

 cally/ " Ciconiine." In all the Herons and Storks dissected by Prof. 

 Garrod the tendon of ihejlexor longus hallucis sends down a vin- 

 culum to join the tendon of the flexor perforans digitorum before 

 the trifurcation of the latter, the vinculum being extremely slender 

 in the Herons and altogether absent in Botaurus stellaris. I find, 

 liowever, that the condition of the deep plantar tendons in Scopus 

 is exactly repeated in Ciconia nigra. In this bird Mr. Forbes ^ has 

 figured a precisely similar arrangement to that which I have de- 

 scribed in Scopus ; the tendon of the flexor hallucis sends off a 

 special slip to digit ii. as well as a vinculum to the flexor perforans 

 just before its trifurcation. 



In the absence of the expansor secundariorum, Scopus agrees with 

 Cancroma and Egretta ^ and the Ciconiidse ; this muscle is present in 

 all Herons except the two genera mentioned. 



The tendons of the patagium do not differ much from what is 

 found in other Herodiones ; the absence of a biceps slip is charac- 

 teristic of both Storks and Herons. 



The muscular anatomy of Scopus, on the whole, appears to com- 

 bine the characters of both the Ciconiidae and the Ardeidae. On 

 myological grounds only it would be difficult to assign it definitely to 

 either group ; in fact, the only features in which this genus espe- 

 cially resembles the Herons and differs markedly from the Storks are 

 the form of the syrinx and the air-sacs, while, as already stated, the 

 arrangement of the feather-tracts and the structure of the skeleton 

 are more particularly Stork-like. It is clear, therefore, that Scopus 

 is in many respects an intermediate type between the Ciconiidse on 

 the one hand and the Ardeidse on the other ; and its relation to 

 both may be seen at a glance from the accompanying table : — 



MSS. 



=* Garrod, Coll. Papers, p. 329. 



