Pleurotomella castanea Dall, 1896 Phymorhynchus castaneus is a species of sea snail, a marine gastropod mollusk in the family Raphitomidae.

It is resembling Phymorhynchus cingulatus (Dall, 1890), of a chestnut-brown color, fading to a paler pinkish-brown, with seven whorls.

The nucleus eroded, the early whorls are with four or five flattened elevated spirals with wider interspaces in front of a somewhat sloping anal fasciole, more or less reticulated by narrow, slender, irregular, elevated riblets in harmony with the lines of growth, and which form on the fasciole delicate arches concave forward.

Pillar is thin, gyrate, attenuated in front, forming a narrowly pervious axis, the whole of a pinkish-brown color.

[2] This article incorporates public domain text from the 1908 reference "Reports on the Dredging Operations off the West Coast of Central America...".