1882.] MR. W. A. FORBES ON THE GREAT ANTEATER. 301 
bones ; running then 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 bone for the greater 
part of its length, not, however, extending to either of its extremities. 
Along the anterior (free) border of the ascending part, at the point 
where it is in contact with the ducts and the deep part of their 
muscular ring, is developed a strong tendinous edge (s.h. m. ¢), the 
‘commissural tendon ”’ of Owen. 
The muscular fibres inserted on this and attached to the stylo- 
hyal (ceratohyal of Owen’s nomenclature) are described by that 
author as the “ cerato-hyoideus,”’ whilst Pouchet more correctly 
applies to it the name of “‘ stylo-hyoideus,”’ the rest of the muscular 
arrangement here described forming, as already stated, the ‘‘con- 
strictor salivaris”’ of both authors. 
It appears to me that the whole muscle may be more correctly 
considered as the stylo-hyoideus, which has developed this remark- 
able course round the submaxillary ducts in order to aid the 
ejaculation of the saliva therein contained by the constriction, on 
contraction of the muscle, of their walls between the circularly-dis- 
posed fibres surrounding them and the tendon developed on its 
anterior margin. 
In the genus Zamandua’ (Plate XV. fig. 2) there is no special 
muscular envelope developed round the ducts in this position. The 
most posterior fibres of the mylo-hyoideus (m.h') arise from the 
posterior end of the stylo-hyal bone, running inwards and forwards, 
and blending internally with the genio-hyoid. To this point also run 
backwards and inwards the fibres of a narrow flattened muscle (s.4. m), 
which crosses the hyoid origin of the mylo-hyoid superficially, and, 
as it arises from the stylo-hyal bone, must be considered to represent 
a stylo-hyoideus. At the point where it meets the genio-hyoid and 
mylo-hyoid, all three muscles become closely connected together, the 
stylo-hyoid developing here an anterior tendinous edge (s./. m. £). 
Between this tendon and the conjoined mylo-hyoid and genio-hyoid 
run the three ducts of the submaxillary gland, so that contraction 
of these muscles here also serves a purpose similar to that produced 
by the more specialized arrangement found in the larger species. 
[P.S. July 13, 1882.—I have found the disposition of the salivary 
ducts and the arrangement of the sty/o.hyoideus muscles exactly the 
same as those here described in a third specimen of Myrmecophaga 
just dead.—W, A. F.] 
EXPLANATION OF PLATE XY. 
Fig. 1. Dissection of the left suprabyoidean region of Myrmecophaga jubata, 
to show the course and relations of the stylo-hyoideus muscle. 
1 Cf. Duvernoy, Mém. Strasb. 1830, ‘Mémoire sur la langue” &c., p. 3. 
