386 NEW YORK STATE MUSEUM 
able evidence, if supported by collateral facts, even though such a struc- 
ture 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 euryp- 
terid parts are casual and the illustrated specimens represent only a very 
slender percentage of the total specimens gathered. Aside from these imper- 
fections of outline there should be, so far as experience goes, a crucial test in 
the matter of integumental sculpture, for everywhere among the fossil mero- 
stomes 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 segmenta- 
tion 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.’ 
1In 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 fossil- 
iferous rock beds. 
