514 Dr. F. A. Bather — Notes on Yunnan Cystidea. 



irregular curved groove across the right side of the theea in its lower 

 third, and this is clearlj'- (perhaps too clearly) shown passing across 

 the drawing. The groove was interpreted, with the specimen before 

 me, as evidence of slight folding accentuated by weathering ; some 

 fainter folds, also the result of post-mortem compression, are obscurely 

 indicated below this main groove, and are brought out in the drawing. 

 If this is all that Dr. Eeed has to offer in support of his ' food- 

 grooves ', he must not be surprised if their existence is denied. 

 Grooves and folds just as clear are shown in specimens of Sinocystis 

 (see pi. I, figs. 6 and 7), a genus in which such ' food-grooves ' are 

 rightly said to be non-existent. 



Clear and undoubted evidence is required, for « ^n'or« arguments 

 are certainly opposed to Dr. Eeed's interpretation. Dr. Eeed 

 compares the alleged food-grooves to those of Fungocystis, Pyrocystis 

 pirum {apud Jaekel), and Gomphocystis. In the two former the food- 

 grooves, as usual in Glyptosphaeridse, cut across the thecal plates and 

 do not follow their sutures. In Gomphocystis certain thecal plates 

 have assumed a more definite arrangement as floor-plates of the 

 grooves, which follow a spiral but quite definite course wholly unlike 

 that described for Ovoeystis by Dr. Reed. In all three genera, as 

 indeed in all Diploporita, the epithecal food-grooves end on exothecal 

 brachioles, of which the facets at any rate are visible. The cover- 

 plates of the grooves are not preserved in all specimens of Diploporita, 

 though the notches for their reception may often be detected ; but in 

 forms with such solid and well-preserved cover-plates as SinocysUs 

 and Ovoeystis, some traces of them would certainly be found on any 

 extensions of the subvective system that might occur. ISFo traces of 

 cover-plates are visible on the alleged extensions in Ovoeystis. 

 Finally in all Pelmatozoa the food-grooves lead to the peristome ; 

 and this arrangement is conspicuous in all Diploporita. In Ovoeystis 

 mansuyi, as in both species of Sinocystis, there is a particularly 

 evident subvective system, with brachiole-facets and strong cover- 

 plates. There is not the smallest trace of any extension from this 

 compact system over the general surface of the theca, nor has 

 Dr. Reed ventured to describe or portray any connection between 

 this system and his vaguely meandering, or longitudinal meridional, 

 or concentric spiral grooves. 



The simple fact is that the thecal plates of Ovoeystis mansuyi are, 

 as Dr. Reed puts it, "thick swollen"; in other words, the suture- 

 lines are depressed. But there is no evidence that extensions of the 

 subvective or any other system passed along these depressions. 



Many specimens of 0. mansuyi (e.g. II, 3, 4, 6, 8, 10) are 

 distinguished from all [?] the specimens of Sinocystis by bearing on 

 some of their thecal plates structures which Dr. Reed calls "small 

 circular isolated raised cup-like pseudo-brachiole facets"; and, 

 when the specimens were in my hands, being unable to discern any 

 other points of difference, I supposed in my ignorance that Dr. Reed 

 had based his genus to some extent on these appearances. Therefore, 

 though not in much doubt as to their true nature, I was led to 

 examine them with some care. This is fortunate, since Dr. Reed 

 seems undecided "whether to interpret these structures as features 



