We record for the first time a nominal species of the genus Microscleroderma in the Western Atlantic, and the first record of the genus Amphibleptula in Mexico. Two new species of ‘lithistid’ Tetractinellida are described: Microscleroderma mexica sp. nov. from crevices of two reefs in Veracruz, Mexico, and Amphibleptula aaktun sp. nov. from the anchialine cave El Aerolito, Cozumel Island, Mexico. Microscleroderma mexica sp. nov. is characterized by its tubular and cup-shaped to wavy laminar habitus, hirsute surface and two size categories of oxea diactines. Amphibleptula aaktun sp. nov. is characterized by its ficiform or lobular habitus with an exhalant area at the flat top of the body, divided into numerous vertical septa-like structures; its desmas have thinner epirhabds, and thinner oxea than those of Amphibleptula madrepora. This is the second species of Amphibleptula that has been described; hence, we propose the redefinition of the genus. Both species described have a shallow distribution (≤21 m depth); they are differentiated from each other by the disjunction between their habitats as well as by their morphology.

中文翻译：

---

来自两个对比鲜明的海洋环境的新种微硬皮病和双翅目（Demospongiae、Tetractinellida、Scleritodermidae）

我们首次记录了该属的名义物种小硬皮病在西大西洋，该属的第一个记录蝾螈在墨西哥。描述了两种新的“石螈”Tetractinellida：墨西哥小硬皮病sp。十一月 来自墨西哥韦拉克鲁斯的两个珊瑚礁的裂缝，蝾螈sp。十一月 来自墨西哥科苏梅尔岛的 Anchialine 洞穴 El Aerolito。墨西哥小硬皮病sp。十一月 其特点是管状和杯状到波浪状的层状习性，多毛的表面和两个大小类别的oxea diactines。蝾螈sp。十一月 其特点是呈丝状或小叶状，在身体平坦的顶部有一个呼出区，分成许多垂直的隔膜状结构；它的desmas 的epirhabds 和oxea 比那些蝾螈. 这是第二种蝾螈已经描述的；因此，我们建议重新定义该属。所描述的两种物种都分布较浅（≤21 m 深度）；它们通过栖息地之间的分离以及它们的形态而相互区分。