[3] Newly hatched juveniles possess a statocyst and paired eyes but mature individuals lack both.

The brain is bilobed and lies just beneath the epidermis close behind the anterior tip of the body; the two main masses consist of a central neuropile and nucleated rind and are connected by a short medial commissure.

[3] The reproductive organs produce a slightly thickened ridge medially in the terminal quarter of the body.

The female pore is prominent and opens to a ciliated vagina located on the ventral body wall immediately anterior to the male gonadopore.

The seminal vesicle, which lies just in front of the posterior notch in the body margin, is most prominent, and appears white from contained sperm.