This section is from the book "Anatomy Of The Arteries Of The Human Body", by John Hatch Power. Also available from Amazon: Anatomy of the Arteries of the Human Body, with the Descriptive Anatomy of the Heart.
The Communicans Profunda should not be dissected till the palmaris superficialis and superficial palmar arch of arteries have been examined. It passes obliquely downwards and inwards, between the pisiform bone and unciform process of the unciform bone, lying superficial to the ligament which connects these bones; it next passes between the origin of the abductor minimi digiti internally, and the origin of the flexor minimi digiti externally; it then turns outwards, beneath the two muscles arising from the unciform process, viz., the short flexor and opponens minimi digiti, to join the palmaris profunda, a branch of the radial, and so to form the deep palmar arch. In this course it is accompanied by a large branch of the ulnar nerve which lies superficial to it.
The Superficial Palmar Artery is usually much larger than the preceding. It winds downwards and outwards, beneath the palmar aponeurosis, to inosculate with the superficialis volae, a branch of the radial artery; and thus forms the superficial palmar arch.