900 MESSKS. B. C. A. WINDLE AND F. G. P.\BSONS ON [DeC. 10, 



specimen (6), the posterior muscle, instead of passing round the 

 front of the leg as it did in our case, wrapped round the back of 

 the thigh, and was inserted just below the insertion of the flexor 

 cruris lateralis. Humphry (2) also found tiie muscle double, but 

 Mackintosh does not seem to have noticed this condition in his 

 specimen. In Chol^xpus we have records of three specimens 

 (8, 9, 10), all of which agree in calling the muscle double. Among 

 the 31t/rmecopha(jidce, Myrmecopha^a (11) has a double muscle, the 

 anterior part of which rises from the ramus of the pubes internal 

 to the ilio-pectineal eminence, and is inserted into the upper 

 two-thirds of the cnemial crest of the tibia. The posterior part 

 rises from the symphysis and descending ramus of the pubes, and 

 is inserted below the last, into the lower part of the cnemial crest 

 and shaft of the tibia as low as the middle of the bone. In 

 Tamandua (14) the muscle rises from the sub-pubic arch, and in 

 section would appear V-shaped, with the apex of the V directed 

 mesially and its concavity including the adductor mass. Though 

 there is no actual line of fission along it, yet the apex of this V 

 clearly is equivalent to the line of separation into anterior and 

 posterior portions in Mtfrmecopluiga. The wide and strong 

 insertion of this muscle is into more than half of the inner side 

 of the tibia. Rapp describes this muscle as very broad in his 

 specimen (15). In Ct/clothwus (17, 19,20) the muscle is single 

 and broad. Among the Dasypodidce the adductor cruris may be 

 either single or double, the latter condition obtaining as far as its 

 insertion into the fascia of the leg from the knee to the ankle in 

 our specimen (22). In another specimen (24) it was single. 

 Galton (X.) describes it as a thin muscle in Dasiipus (23), but 

 Macalister (VII.) says that it is broad in Tatusia (25). In 

 Chlamydophorus (27, 28 n) it is single and thin. In the Manidce 

 the muscle may also be single or double. In two cases (32, 34) 

 it fell under the former category, and in other two (29, 33) under 

 the latter. In all cases the muscle is of specially large size in this 

 family. In the Orycteropodidce (35, 36, 37) the adductor cruris is 

 single and broad. 



Semimembranosus. — In all the Edentates the semimembranosus 

 is a very constant muscle rising from the tuber ischii and part of 

 the ramus, and obtaining insertion into the upper part of the 

 internal surface of the tibia, deep to the long internal lateral 

 ligament. The tibial insertion is especially extensive in the 

 Dusypodidce, and it is remarkable that in these animals the long 

 internal lateral ligament is attached nearly as low as the middle of 

 the tibia. 



Presemimembranosus. — By many observers this has not as yet 

 been recognized as a separate muscle, some including it in the 

 adductor mass, others describing it with the semimembranosus. 

 Haughton calls it the adductor primus ; Macalister, the adductor 

 magnus condyloidea. In our specimens of Bradypits (1) and 

 CTiolcepus (8) it was a perfectly distinct muscle, rising from the 

 tuber ischii, and being inserted into the femur just above the 



