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



obscure, perhaps over-grown, for it may be mentioned that there are 

 several cystid roots adherent to the specimen, as in Sinocystis 

 mansuyi. The facets are, as usual, on Adorals II. Adorals I 

 consist of the usual 2 posterior, 2 anterior, and 1 left; but on the 

 right side, instead of the single adoral between two facets, there 

 appear to be two adorals with the food-groove passing between 

 them; thus there is the unusual number of seven Adorals I. 

 Adorals It seem from the drawing to form a very irregular circlet of 

 10 or LI unequal plates; the irregularity is greater on the right side. 

 Miller & Gurley's description does not altogether correspond with 

 the preceding account based on their figure. This is due probably 

 to the peculiar morphological views of S. A. Miller. They write 

 (1894, p. 6) : " On each side near the bottom of the ambulacral 

 furrow there is a row of pores, but a free plate of the same character 

 from the same or a similar species, when examined from below, does 

 not show these pores in lines, nor can they be distinguished from the 

 other pores that penetrate the plate from all sides. The ambulacral 

 furrow, therefore, is not homologous with the ambulacral furrows of 

 either crinoids or blastoids. There is no reason to suppose that it 

 was a food-groove, was covered with minute plates, or was furnished 

 with pinnules. It appears as a triangular furrow cut only half-way 

 through the plates, and where following the suture lines of plates, 

 the plates are more firmly joined than elsewhere by the denticulated 

 edges, but when it enters upon a plate that bears an arm the furrow 

 runs up to the base of the arm where it does not cut one-fourth of 

 the thickness of the plate, and where the pores upon the sides appear 

 to differ from the other pores that penetrate the plate only by being 

 arranged externally in two lines." Of course the "furrow" is 

 homologous with the food-grooves of all other Pelmatozoa, and there 

 is every reason to suppose that it had cover-plates. Whether the 

 cover-plates are preserved in this specimen or no is a different 

 question. It is most natural to suppose that they have here been 

 exceptionally preserved, just as they are preserved as a rule in the 

 specimens of Sinocystis; further, as in some of the latter, there is 

 a slight furrow between the cover-plates in some parts, as shown in 

 text-fig. 10 and discussed on p. 535 (antea, 1918). The pores 

 mentioned by Miller & Gurley are, no doubt, the diplopores, which 

 are occasionally ranged alongside the food-grooves. 



In specimen E 7673 (fig. 29) only three facets can be distinguished, 

 but the arrangement differs from that of either of the two specimens 

 just considered. The specimen is strongly pustulate and is crushed 

 in the left-anterior -right-posterior plane ; on the posterior half of 

 the adoral face the intervals between the pustules were filled 

 with a matrix not easily distinguishable from the stereom and 

 removed only with difficulty; on the anterior half of the adoral face 

 the plates are weathered and worn down. The facets preserved are 

 the two on the left and the right posterior. Adorals I are 9 or 10, 

 probably the latter. Two of these border each food-groove, and 

 enter into the adoral half of the facet. That accounts for six plates. 

 One Adoral I is in the posterior interradius, and three rather large 

 plates are on the anterior border of the peristome. The adoral third 



