aculeus

A large vesicle terminates in a sharp and long aculeus (stinger).

Onoba aculeus (Gould, 1841)

The pedipalp pincers are massive while the metasoma is proportionally thin with a small vesicle and stinger (aculeus).

Turbonilla aculeus (C.B. Adams, 1852)

The telson, in turn, consists of the vesicle, which holds a pair of venom glands, and the hypodermic aculeus, the venom-injecting barb.

Turbonilla aculeus is a species of sea snail, a marine gastropod mollusk in the family Pyramidellidae, the pyrams and their allies.

It was probably derived from the adjective aculeus, meaning "sharp, pointy, prickly," or "thorny," and may have been a commentary on the acuteness of its bearer's mind.

For example, Microphallus pseudopygmaeus chemically castrates its host, the snail Onoba aculeus, and causes it to grow larger than normal.

Onoba aculeus, common name the pointed cingula, is a species of minute sea snail, a marine gastropod mollusk or micromollusk in the family Rissoidae.

William of Tyre described Baldwin as "a devout and God-fearing man, notable for his loyalty and for his great experience in military matters," and said that he was nicknamed "the Thorny" (cognominatus est Aculeus).