Fig. 8 in On Kincaidiana Altman, 1936 and Guestphalinus Michaelsen, 1933 (Annelida, Clitellata, Lumbriculidae), with the descriptions of three new species

Fig. 8. Guestphalinus exilis Fend & Rodriguez sp. nov., reproductive structures, all oriented with anterior end to left. A–C from Squaw Creek (the type locality), D from the South Fork Eel River A. Segments VIII–XI of a mature worm, showing reproductive organs; anterior vas deferens broken at spermatheca. B. Segments IX–X of a recently-mated worm; spermathecal ampulla not yet developed; atrium expanded. C. Segments IX–X of a partially-mature worm; atrium and spermathecae tubular, but copulatory glands well-developed; ental end of spermatheca missing. D. Segment IX of a partially-mature worm; glands well developed; atrium and spermatheca small, tubular.