1899.] THE MYOLOGY OF THE EDENTATA. 995 



femur just above the interual condyle. The rest of the mass came 

 from the sub-pubic arch and was inserted into the middle third of 

 the femur. The other two specimens of which we have records 

 (2, 5) were dissected at a time when the presemimembranosus 

 was as yet unrecognized as a separate muscle, and we suspect that 

 the description of this muscle is included in that of the adductors. 

 It is worth noting that the pectineus and adductors rise as near 

 the middle line of the body as thej can, and wrap well round 

 the back of the femur so as to act powerfully as external 

 rotators. In Cholcepvs (8), when the presemimembranosus is 

 kept separate, the addu^ctors closely agree with those of Bradypus. 

 Amoug the Myrmecophagidle, Miirwecophaga has the mass divided 

 into two planes, the more superticial of which rises from the hori- 

 zontal ramus and anterior half of the symphysis of the pubes and 

 is inserted into the lower half of the femur. This part is pierced 

 by the branch of the obturator nerve to the posterior adductor 

 cruris (gracilis), and possibly, therefore, corresponds to the human 

 adductores longus et brevis. The more posterior part of the mass 

 has the same origin as the last, but lies deep to it and obtains 

 origin from rather more of the symphysis ; it is inserted into the 

 lower two-thirds of the femur, and probably corresponds to the 

 human adductor raagnus. The whole of the adductor mass is 

 supplied by the obturator nerve. In Tamandua (14) two layers 

 can also be made out, both inserted below the middle of the femur. 

 Eapp (15) says of this animal that the adductors cannot be divided 

 into three layers. In CydotJiums, Humphry (17), Meckel (19), 

 and Galton (20) were all able to distinguish three layers, but pos- 

 sibly one of these was the presemimembranosus. The Dasypodidm 

 (Dasypiis 22, 2'S, Tatusia 25, and Chlamydopjhorus 27, 28, 28rt), all 

 present an indivisible adductor mass. ]n ihit Manidce we were able 

 to make out three distinct parts, viz., (a) to the outer border of the 

 femur above the condyles under cover of the outer head of the 

 gastrocnemius (which reaches unusually high up), tliis is probably 

 adductor longus ; (6) to the middle third of the femur (adductor 

 brevis) ; and (c) the most posterior (adductor magnus) to the lower 

 part of the femur. In other specimens (32, 33, 34) tlie dissectors 

 all agree that three layers can be seen. In the Orycteropodidm 

 (35, 36) three layers are also described. 



Adductor cruris {Gracilis) .— Vae^ Bradypodida seem remarkable 

 for The constant presence of a double adductor cruris, but the 

 insertion diifers from that which one is accustomed to associate 

 with the double condition of that muscle amongst the Mammalia. 

 In our specimeu of Bradypms (1) the anterior adductor cruris 

 rose from the inner part of Poupart's ligament, and was inserted 

 into the upper part of the inner surface of the tibia. The 

 posterior rose from the symphysis pubis, and, after reaching the 

 knee, passed in front of the shaft of the tibia to be inserted into 

 the fascia on the outer side of the leg below, and continuous with 

 the insertion of the flexor cruris laterahs (biceps). Both parts 

 w^ere supplied by the obturator nerve. In Cuvier and Laurillard's 



