"Male of Balanoglossus (Dolichoglossus) kowalevskii. Note anterior proboscis. Mo., Mouth; op., slight operculum behind the collar; then the region with gill-slits; ts., testes; a., anus." -Thomson, 1916

Balanoglossus

"Male of Balanoglossus (Dolichoglossus) kowalevskii. Note anterior proboscis. Mo., Mouth; op., slight…