Internal Anatomy (Pl. 5, Fig. 2)

Alimentary Canal. The pharynx is rounded and muscular and occupies the first four segments. There is a short, thin-walled proventriculus in v, opening into an elongate gizzard with thick, muscular walls in vi and vii. The oesophagus extends from viii to xvii and lacks oesophageal glands. The intestine commences in xviii, is thin walled, and has a typhlosole.

Vascular System. The dorsal blood vessel is unpaired throughout its length. There are four pairs of hearts, a pair in each of x, xi, xii and xiii.

Reproductive System. There are two pairs of testes, a pair in x and a pair in xi, and a pair of ovaries in xiii. Two pairs of very minute spermathecae are situated in viii and ix and open to the exterior at 7/8 and 8/9. Each is a small, laterally flattened thin-walled, ovoidal sac, opening into a round, thick-walled muscular atrium which opens to the exterior by a short, narrow duct. There is a very small, rounded diverticulum, with a narrow duct, opening into the lateral aspect of the atrium. (Pl. 5, Fig. 3.) There are two pairs of uncoiled tubular prostates, a pair in xvii and a pair in xix, each pair confined to the one segment. I could not see any penial chaetae, but the very small size of the worm makes it very difficult to see many of the organs. There are two pairs of small, racemose vesiculae seminales, a pair in xi and a pair in xii.

The nephridia are minute, convoluted, tubular structures which open into a small, transparent vesicle before discharging to the exterior.