able evidence, if supported by collateral facts, even though such a structure is vastly progressed over what we might deductively expect in these ancient organisms. Speaking broadly however the outlines of all these bodies that we have examined, are indeterminate; we can not avoid the conviction that such resemblances as have been indicated to eurypterid parts are casual and the illustrated specimens represent only a very slender percentage of the total specimens gathered. Aside from these imperfections of outline there should be, so far as experience goes, a crucial test in the matter of integumental sculpture, for everywhere among the fossil merostomes this structure is a guide and index even in inconsiderable fragments. There is no reason to assume the absence of this sculpture even in archaic or ancestral forms of the group, but in all the specimens of Beltina we have scrutinized there is no trace of it; nor is there of body segmentation or arm joints. Many of the Beltina bodies are bandlike fragments or patches which indicate an infolding or overlapping as though they had been floated into the muds as very thin and tenuous films rather than as the rigid parts of an arthropod test. We entertain no doubt that these bodies, or the greater part, are of organic origin and while unable, after careful study, to convince ourselves that they are merostomatous, yet to renewed efforts in the field they do give promise of a recognizable fauna.[1]
- ↑ In a quite recent paper (Smithsonian Miscellaneous Collections. Middle Cambrian Merostomata, April 8, 1911) Dr Walcott has given figures of additional specimens referred to Beltina danai, from new horizons regarded as Algonkian, the Altyn limestone, near Altyn, Montana, and a silicious rock in Alberta, Canada. These retain a certain degree of convexity and show a defined merostome sculpture [pl. 7, fig. 2–4], while figures 3 and 4 give clear outlines of merostome segments. It is not quite clear on what basis of structure these very evident merostome remains are identified with the Greyson shale examples of "Beltina" though they intimate the extremely ancient age of the Merostomata and their extraordinary specialization in the earliest fossiliferous rock beds.
