Proceedings of the Zoological Society of London, London, Academic Press, periodicals, zoology, The illustration features two distinct fish species. The top section depicts a Tetraodon pleurostictus, characterized by its rounded body and pronounced eyes, showcasing its unique shape and points of interest. Below it, the Mormyrus lepturus is presented, noted for its elongated and slender form, with a distinct head profile. Each species is meticulously labeled, highlighting their anatomical differences and contributing to an understanding of their classification within aquatic biology.