Table 1 Differences between originally described characters of Helminthope psammobionta and results of this study

Optic and buccal ganglia innervated by

branches of ‘terminal cerebropleural connective’*

opg: optic nerve parallel to N4 bg: ventral sides of cpg

Buccal ganglia located

behind statocysts/pedal ganglia

anterior to pedal ganglia

Pedal ganglia

with pronounced anterior lobes

spheroid

Visceral = abdominal ganglion

with ‘chiasma of fibres’ indicating streptoneury

?without traces of streptoneury

Paired visceral nerves

with anterior-running branches [29:Figure 4]

not branching

Postcerebral accessory ganglia

not described

on N4, pedal nerve, ?opgn

Vesicle filled with spermatozoa is

a ‘spermatheca’ distal to nidamental glands

an ampulla proximal to nidamental glands

Gonad

‘appears ramified’; protandric, possibly gonochoric

~ tubular; hermaphroditic (possibly protandric)

Externally visible tube below CNS is

anteriormost part of genital system (genital opening ‘still appears to be absent’)

single tubular salivary gland

Ciliated opening at right body side

is ‘(reduced) mantle cavity’ (= anus and protonephridiopore)

is genital opening

Intestine located

approx. 100 μm behind visceral ganglion

in posterior fifth of body

Ventroterminal adhesive gland

not detected/ missing

present