Internal Anatomy (Plate 119, fig. 2)

There are no specially thickened septa.

Alimentary Canal. A strongly muscular pharynx occupies the first four segments. A thin-walled proventriculus in v joins the pharynx to the long thick-walled muscular gizzard in vi. The oesophagus extends from vii to xvii and opens into the wide thin-walled intestine in xviii. There are no oesophageal glands. The intestine lacks a typhlosole.

Vascular System. The dorsal blood vessel is paired throughout its length. A slender supra-intestinal vessel runs along the mid-dorsal line of the oesophagus from × to xiii and the four pairs of hearts arise from that vessel, a pair in each of the segments × to xiii.

Reproductive System. Two pairs of testicular funnels are present, a pair in each of × and xi, but the testes were not visible in the specimen examined. The ovaries are easily identifiable in xiii and consist of a group of moniliform threads attached to the anterior septum of the segment, ventro-laterally on each side. There are two pairs of spermathecae, a pair in viii and a pair in ix. Each spermatheca consists of an antero-posteriorly flattened conical sac opening by a narrow duct to the exterior, close to the anterior septum of the spermathecal segment. Five small digitate diverticula are grouped around the base of the sac and open into the duct. (Plate 119, fig. 3.) Two pairs of prostates are present, a pair in xvii and a pair in xix. They are extremely convoluted, slender, tubular organs and are confined to a single segment in each case. There are neither penial chaetae nor copulatory muscles associated with the prostates. The vesiculae seminales are paired racemose organs lying lateral to the oesophagus in xi and xii.

Micronephridia occur in the form of a band of long slender tubules on the ventro-lateral and lateral aspects of each side of every segment except i.