vermis

...The cerebellum is one of the motor centers and is thought to play an important role in so-called "motor learning," such as practicing sports or playing a musical instrument, but it is also involved in regulating autonomic nervous function (Figure 2).
[Structure of the cerebellum]
The cerebellum is divided into the vermis, which extends from the front to the back at the midline, and the cerebellar hemispheres, which extend from the vermis like wings to the left and right. The part of the cerebellar hemisphere closest to the vermis is called the intermediate part to distinguish it from the lateral part.

*Some of the terminology explanations that mention "vermis" are listed below.

Source | Heibonsha World Encyclopedia 2nd Edition | Information

…小脳は運動中枢の一つであり，スポーツや楽器弾奏の練習など，いわゆる〈運動学習〉に重要な働きをすると考えられるが，自律神経機能の調節にも関与している(図2)。
［小脳の構造］
　小脳は外見上，正中部で前後に伸びる虫部vermisと，これから左右に翼のように張り出す小脳半球に分けられる。小脳半球の虫部寄りの部分は，外側部と区別して中間部と呼ばれる。…

※「vermis」について言及している用語解説の一部を掲載しています。

出典｜株式会社平凡社世界大百科事典 第２版について | 情報