310 ON THE ANATOMY OF 



" apohyal " by Poucbet, but, according to the nomenclature now ordi- 

 narily employed, must really be the cerato-hyal *. The other two long 

 curved ossifications of the anterior cornu must therefore be the epi- and 

 stylo-hyals respectively. 



Both Rapp (I. c. p. 61) and Pouchet (' Memoires/ p. 95, pi. xii. figs. 

 1-3) describe the posterior cornu as articulating externally with the 

 anterior one. But in neither of my specimens can I find any evidence 

 of such a joint, as the two cormta, when in their undisturbed condition, 

 are separated by a considerable space, in part occupied by a muscle (the 

 inter cornualis, Owen, 1. c. p. 127) ; and in the cleaned bones I also find 

 it impossible, without violence, to bring the two arches into such contact 

 together. In Tamandua, though there is a distinct ligament between 

 the two arches, they are nevertheless similarly separated; and neither 

 Duvernoy f, who dissected this species, nor Owen, in his account of 

 Myrmecophaga, allude to any such interarticulation existing ; Owen's 

 figure (pi. xxxix. fig. 2) indeed clearly shows the two cornua separated 

 by the intercornualis muscle, as also observed by me (cf. Plate VIII. fig. 1, 



in*). 



At the place where the three main ducts of the submaxillary glands of 

 each side converge to become intimately connected together by their 

 walls, though they still remain quite separate tubes, they are covered by 

 a mass of muscle which forms a bulb-like swelling for an extent of 1| 

 inch on the inferior aspect of the conjoined ducts (Plate VIII. fig. 1). 

 It is this mass of muscles that has been described by Owen (I. c. p. 126) 

 as the " constrictor salivaris" a name adopted by Pouchet subse- 

 quently. 



The external aspect of the ducts is also, for the posterior half inch of 

 this space, covered by a thick muscular coating, so that in this portion 

 the three ducts are encircled by a broad ring of muscular fibres. These 

 fibres arise from the anterior edge of the anterior hyoid coruu, on each 

 P.Z.S. 1882, side of the junction of the stylo- and epihyal bones; running then 

 p. 301. forwards and outwards, they pass beneath and to the outside of (in a 

 sternal view) the conjoined ducts, and then ascend to fan out and form 

 the muscular bulb. The more anterior of these fibres are inserted into 

 the internal and upper part of the combined ducts, and cease there. 

 The most posterior, on the contrary, completely encircle the ducts, 

 running inwards over the ducts, and then, recurving on themselves, 

 ascend on the deep aspect of the ducts, to be inserted on the stylohyal 



* In Tamandua I am unable to find any corresponding ossification, though both the 

 epi- and stylo-hyals are well developed. 



t Mem. Soe. Hist, Nat. Strasbourg, 1830; and Cuvier's Anat. Conip. 2nic ed. iv. 

 part 1, p. 476. 



