CALAMOSPORA 



49 



teration, the important point relates to 

 recognition of the degree of change that 

 is manifested and of the fact that bio- 

 character modification has proceeded at 

 different rates in the different organs and 

 parts of the plant life cycle. In order 

 that fossil identifications may be scien- 

 tifically trustworthy these principles 

 should be more widely acknowledged. 

 Alisporites is a designation that should 

 be very useful in reporting the occurrence 

 of caytonian spores and others of the 

 same sort which perhaps may not even 

 be necessarily referable to that group. 

 Whether the Caytoniales are worthy of 

 ordinal distinction is perhaps subject to 

 some question now that Harris (1941, 

 1940) has shown so convincingly that 

 they are gymnospermous and have no 

 particular connection with angiosperms. 

 Likewise whether they should be termed 

 pteridosperms is still perhaps too much 

 a matter of individual opinion. The 

 problem of caytonian relationship with 

 other gymno'Spermae is a perplexing one 

 which may find its truest solution in the 

 exacting study of fossil pollen grains 

 similar to Alisporites, Parasporites, and 

 Pityosporites. 



The more adequate generic definition 

 of Alisporites should be taken up in con- 

 nection with such studies. Daugherty's 

 generic distinction of these interesting 

 plant microfossils is a forward step which 

 will provide a much more precise means 

 of referring to them. They can be dis- 

 tinguished from spores of Parasporites 

 by their lack of a trilete commissure and 

 probably in their distal mode of exit; 

 from Pityosporites in having the bladders 

 placed opposite one another and not in- 

 clined distally, also in their lack of a 

 thick proximal cap. Although it would 

 seem possible to recognize morphologic 

 homologies between the parts of Alispo- 

 rites pollen and the spores of Endospo- 

 rites and those of other cordaitaleans, 

 these genera seem more distantly related 

 and are easily distinguished. Pollen sim- 

 ilar to that of Lehachia and Walchiantkus, 

 now placed in the new genus Florinites 

 (p. 56), is distinguished from pollen of 

 Alisporites by the presence of an annu- 

 late bladder. 



1. Alisporites opii Daugherty, 1941, Carnegie 

 Inst. Washington Pub. 526, p. 98, pi. 34, 

 fig. 2. ! 



2. Alisporites spp. ? 



Pollen Forms I, II, and III, Liick, 

 1913, Beitrag zur Kenntnis des alteren 

 Salzgebirges im Berlepsch — Bergwerk bei 

 Stassfurt nebst Bemerkungen uber die pol- 

 lenfuhrung des Salztones, pp. 29-31, figs. 

 53-56, 58-59. 



Genus Calamospora S. W. and B., gen. 

 nov. 



Plate 3, figures 22-22b ; text figure 1 



Symmetry. — Spores trilete ; radial. 



Shape. — Spherical or nearly so ; when 

 compressed, readjustment to a disk-like 

 form leads to formation of characteristic 

 sharp taper-point folds of variously cres- 

 centic or narrowly lenticular outline. Some- 

 times the spores are folded double so that 

 the whole external outline is sharply len- 

 ticular. Such folds are one of the char- 

 acteristic features of the genus. 



Size. — Highly variable from about 40 

 microns (or smaller in some abortive 

 specimens), to several hundred microns 

 in diameter. 



Ornamentation. — Spores are character- 

 istically very smooth in general appear- 

 ance ; on closer inspection they may be 

 minutely granulose or slightly rugose. 

 There may be very slight differentiation 

 of proximal pyramic areas shown by this 

 almost negligible emphytic marking. Larg- 

 er spores often possess a high gloss when 

 observed by reflected light. 



Haptotypic structures. — Trilete rays 

 notably short; usually they do not ex- 

 ceed one-half the length of the spore 

 radius. The suture line is distinct and 

 attenuate ; sometimes moderate lips are 

 developed. Arcuate ridges are commonly 

 not distinguishable although they may be 

 present as slight rounded thickenings. In 

 some forms the pyramic areas have a 

 somewhat different surface texture than 

 the rest of the spore coat. 



Spore coat. — Relatively thin. Spores 

 less than 100 microns diameter are gen- 

 erally yellowish and highly translucent ; 

 larger spores (which certainly are mostly 

 megaspores) are progressively less trans- 

 lucent as the wall thickness increases rel- 

 ative to the spore diameter. Actual wall 

 thickness thus is highly variable in vari- 

 ous species, ranging from about 15 microns 

 in forms over half a millimeter in diam- 

 eter, to less than 2 microns in those 

 smaller than 100 microns. A very thin 



