586 MR. J. C. GALTON ON THE MYOLOGY OF 



digit passes a short, but strong, rounded tendon or ligament from the anterior edge of 

 the sesamoid included in the annular ligament. 



Neither Meckel, Rapp, nor Pouchet makes any mention of the presence of a sesamoid 

 in the tendinous expansion of the deep flexor in the species of Anteater which they 

 severally describe. Such an ossicle is present, however, in Chlamy dopho rus , as well as in 

 Dasypus sexcinctus, as I have mentioned in my paper on the latter species of Armadillo. 



Pronator quadratus. — This muscle, which is described as " small" by Prof. Humphry, 

 was very well developed and of considerable extent in the specimen which I examined. 

 It filled the whole interosseous space of the forearm, as well as the anterior face of the 

 radius and ulna, from the level of the insertion of the biceps and brachialis anticus to the 



distal extremity of the two bones. 



This muscle has a great resemblance to its homologue in the Great Anteater, as repre- 

 sented by Pouchet in his monograph (pi. iv. fig. 3), having a strong tendon running 

 across it obliquely at the junction of its middle with its lower third. This muscle is, 

 moreover, described by the same author as occupying three-quarters of the extent of the 

 forearm 1 . 



Meckel, in his monograph upon the Two-toed Anteater, makes no mention of this 

 muscle when describing the myology of the animal 2 . 



According to Rapp 3 , the pronator quadratus is present in 21. tamandua. Cuvier, 

 moreover, just slightly indicates the distal extremity of the muscle in one of his plates 

 of the myology of this animal 4 , but gives no representation of it in his drawings of the 

 anatomy of the two-toed species. 



Ts T o indication of the presence of this muscle is given by the same anatomist in his 

 plates of the Three-toed Sloth (" Ai"). 



I have already described this muscle as absent in Dasypus sexcinctus, and have, 

 moreover, referred to Meckel's description of its peculiarities in the Ai. 



Lumbricales . — Are four in number, and are well developed. One passes to the radial 

 side of each digit, being inserted into its proximal phalanx. In the case of the index, 

 " middle," and " fourth " digits, this attachment is effected through the medium of a 

 tendon; but the muscle destined for the "little" finger continues fleshy up to its 

 insertion, where, moreover, it is broader than at its origin. These muscles do not 

 appear to have any connexion t 



- 



connexion with the sheaths of the extensor tendons. The three 

 outermost rise together, but quite distinct, from the expanded common tendon of the 

 flexor profundus. That passing to the "little" finger rises from the same tendon, but 

 a little more posteriorly ; so that a few of its hindermost fibres of origin fuse with 

 the terminal fibres of the enormous muscular mass which rises from the inner condyle 

 of the humerus, and from which is given off the muscle which is the representative of 

 the flexor sublimis and palmarls longus. Close to the radial side of the last-described 

 lumbricalis, rises a thin flat slip from the tendon of the deep flexor, which passes under 

 the annular ligament to terminate at the inferior surface of the flexor sublimis. 

 The lumbricales are very fairly represented by Cuvier in one of his plates 5 . 



' digiti.—A small muscle. It arises from the palmar process of the 



Op. cit. p. 17. 



Op. cit. p. 48. * p. cit. pi. 263. fig. 2. 



Deutscher Archiv, V ter Band (Halle und Berlin, 1819). 



5 



Op. cit. pi. 256. fig. 5. 



