An unusually medial axillary arch muscle.

In the left upper limb of an adult male cadaver a triangular muscular slip, 3.5 cm long and 2.5 cm wide, arose from the lower border of latissimus dorsi just proximal to its tendon of insertion. It was inserted by a slender 6 cm long tendon mainly into the coracoid process of the scapula. Three short fibrous strands radiated from this slender tendon to gain attachments to pectoralis minor and the common tendon of origin of the short head of biceps brachii and coracobrachialis. In addition 2 flat tendinous bands attached the margin of this muscular slip to teres major. The thoracodorsal nerve entered the main bulk of latissimus dorsi close to the muscular slip but did not supply a separate branch to the latter. This is an axillary arch muscle in an unusually medial location.