Terminology; Preparation of specimens; Range and distribution of the productoidea; External mophology of the productoidea; Internal morphology of the productoidea; Life habits of the productoidea; Origin of the productoidea; Classification of the productoidea; Systematic descriptions.

Atrypida (Brachiopoda, Rhynchonellata) are ancient marine invertebrate fossils that are well preserved, abundant and diverse in the mid-Paleozoic (ecological evolutionary unit (EEU) P3). Atrypides thus serve as useful tools for morphological shape study. While qualitative studies have been performed for solving problems in brachiopod taxonomy, phylogeny, evolution and ecology, quantitative studies have been lacking. After qualitative taxonomic identifications, morphological shape of the Silurian-Devonian Eastern North American atrypids was analyzed using geometric morphometrics, placing the results in evolutionary and ecological perspectives. Landmark analysis was performed on dorsal valves, ventral valves, anterior and posterior regions. These data were used for comparison with morphological distances, calculated as pairwise Procrustes distances. Evolutionary divergence times were determined from atrypide phylogeny and from stratigraphic zonations in the Michigan Traverse Group. Maximum likelihood tests were performed to determine evolutionary rates and modes of morphological divergence within and between genera. Episkeletobionts on hosts were examined to determine how morphological variation affected these assemblages. Morphometric results suggest that morphological distances within each genus was as large as those observed between genera. Thus, referring individuals to a particular genus, based on shell shape alone is challenging. Diversifying selection has been acting on morphological divergence of these generic pairs and morphometric distances are consistent with the prior phylogenetic arrangement. Short term changes observed in individual lineages, that gets averaged out in time when compared to other genera, together with considerable morphological overlap observed between genera in P3 EEU, suggests a pattern consistent with stasis, as expected in EEUs. The Traverse Group atrypid species lineage, which represents a 5 m.y. time span, exhibited lightly constrained morphological evolution, reflecting a stasis-like pattern. Greater encrustation preferences on one of two morphotypes on the dorsal valve and posterior region, suggest greater surface area facilitated by relatively deeper profile hosts in their reclining life orientation. Overall, the integration of various paleontological datasets reveal that the seemingly homogenous group of atrypide brachiopods exhibit subtle but significant evolution in their shell shape that is correlated with several kinds of ecological differences.

The book describes the morphology and the functions of the various organ systems of the brachiopods, covering recent lingulids, discinids, craniids, rhynchonellids, terebratulids and terebratellids. It includes the relevant previous publications on the subject and the author's unpublished original observations. Of interest is his illustration of separate periostracum-forming epithelium and skeleton-forming epithelium at the periostracal groove or crypt in Lingula postlarva and Discinisca shelled larva. This serves as an alternative to the interpretation of Williams and Wright (1970) that there was a single epithelium, every individual cell of which moved from the periostracal groove or crypt to the mantle edge like a roller belt and secreted in succession pellicle, periostracum and when it went over the mantle edge, the cell secreted primary layer and finally secondary layer of the skeleton. The author next shows that in the earliest Lingula anatina larva and Discinisca coralliphila shelled larva there was no cuticle connection between the dorsal and the ventral valves, disputing Yatsu's (1902) notion that Lingula valves originated by the bending of a single circular shell. The author's illustration also shows that the intestine and anus of L. anatina larva are present at the 2 p.c. stage after it hatches, disputing Yatsu's (1902) claim that they formed during the 4 p.c. stage. The author also illustrates a rare 10 p.c. L. anatina larva from the Johor Strait with longitudinally divided median tentacle, disproving Yatsu's (1902) notion that the median tentacle atrophied after larval settlement. The author illustrates the differentiation of haemerythrocytes and spindle cells from the mesothelium in the mesothelial ridges of the roof and the floor of the perivisceral cavity, establishing that the spindle cells are a normal constituent of the coelomic fluid and disproving the notion that spindle cells differentiated from muscles fibres. The author spent much time in China, sorting, examining and photographing the exceptionally preserved Lower Cambrian Chengjiang fossils in the various institutions. His revision of the published accounts of them by Chinese palaeontologists and his revision of recent inarticulate brachiopods are presented. It is hoped that his observations and conclusions can earn general acceptance.

The growth history of a brachiopod is entombed in its shell, but research on fossil and living brachiopods has generated unanswered questions about these marine invertebrates. Several contributors to Brachiopods Past and Present comment on their differing structures and morphological detail. They use these as examples of ontogenetic and evolutionar