No Crustacean exhibits this trilobite form.
- Five stages in the development of the trilobite Sao hirsuta.
40) is also similar to a Trilobite so far as its segmentation and trilobation are concerned.
The bi-ramose structure of the post-oral limbs, demonstrated by Beecher in the trilobite Triarthrus, is no more inconsistent with its claim to be a primitive Arachnid than is the foliaceous modification of the limbs in Phyllopods inconsistent with their relationship to the Arthrostracous Crustaceans such as Gammarus and Oniscus.
- Four stages in A B C D ° ```' the development of the trilobite Agnostus nudus.
- So-called " trilobite stage " of Limulus polyphemus.