The appendicular muscles of Necturus rnaculosns. 409' 



and closely associated with that of c). Portion c) is perhaps a 

 little the largest, slightly exceeding a). It arises from the median 

 line along approximately its middle three-fifths, and is overlapped 

 anteriorly by aj. It inserts into the crista ventralis. 



The more posterior of the two main portions arises from the 

 muscular ridge (crista muscularis) which characterises the posterior 

 half of the ventral surface of the puboischium, and occupies with 

 its origin nearly the posterior third of this latter piece. Its fibers 

 are directed forwards and outwards, and run beneath (dorsal to) 

 the other portion, which must tlms be reflected in order to expose 

 the insertion. This latter is upon the shaft of the femnr dorsal 

 to the crista ventralis, and is hence more dorsal in position than 

 that of the anterior portion. 



M. pnbotibialis (pt). This is a narrow muscular band, which 

 lies along the inner side of the leg. It arises by a tendon from 

 the projecting angle upon the margin of the puboischium, immediately 

 anterior to the acetabulum, a protection which seems to have not 

 received a name as yet, and which may be called the pre-ace- 

 ta bular process. The fibers of this muscle form a narrow ribbon, 

 which runs along the side of the femur, parallel to its shaft, and 

 becomes inserted by a short tendon into the proximal third of the 

 shaft of the tibia upon its lateral aspect. The most posterior fibers 

 of this muscle are semi-distinct from the rest, and insert in variable 

 numbers into the tendon of M. puboischiotibialis. 



M. i seh iofem oral is (isf). This small muscle arises from the 

 outer margin of the tuberosity of the ischium and lies in the same 

 plane as the skeletal plate, being covered ventrally by both pubo- 

 ischiotibialis and the posterior portion of the puboischiofemoralis 

 externus. The fibers of this muscle converge from their origin and 

 form a tendon, which inserts into the crista lateralis of the head 

 of the femur. 



2. Caudal muscles attached to the posterior 

 appendicular skeleton. 



M. ischiocaudalis (ic). 



M. caudalifemoralis (cf). 



M. caudalipuboischiotibialis (epit). 



These three closely associated, ribbon-like bands lie in a common 

 sheath formed principally by the ventral mass of the trunk muscles. 

 with the aid of the cloaca, which forms the medial wall. Of the 



