"Compleat" is an archaic form of "complete" and can be found in the titles of many older books purporting to be a "complete" compilation of information on a subject. This document on trilobites is far from being a complete presentation about trilobites -- that takes volumes -- thus the "semi-compleat". It is also a pun on the state of most trilobite fossils, including some of the examples here :-)
Back to the "semi-compleat" trilobite page.