910 DR. P. A. BATHER ONT 



that his species could not be a Hypocrinus. So long as there was 

 only one specimen known, it might have been legitimate to evade 

 some of those difficulties by a vague hypothesis of abnormality, 

 or, more precisely, to have supposed that the anus occupied its 

 usual position opposite the small basal (which region is worn 

 away in the holotype), but that it had become choked, and that a 

 new outlet had been formed by the partial resorption of that 

 radial which in the present paper is called r. post. R, but which, 

 on that interpretation, would have been ant. R,. When, however, 

 Dr. Wanner informs me that all his new specimens agree in this 

 curious position of the opening, and that none of them shows any 

 trace of an opening on the opposite side of the theca, then I am 

 bound first to accept the identification by Rothpletz, and after- 

 wards to face the difficulties involved. 



The measurements of the periproct in millimetres are : height 5 ; 

 width below, 5*4 ; left lower margin 3-9 ; right lower margin 27. 



There is no trace of any periproctal plates, unless they are to be 

 sought in the minute plates between the left posterior and right 

 anterior radials. 



Ornament. — In addition to the growth-lines already mentioned, 

 there are to be seen on the better-preserved infrabasals, i. e. on 

 the posterior side, traces of pustules, apparently coinciding with 

 the growth-lines. There also seem to be similar pustules on a 

 small tract of the posterior basal. The rest of the surface is too 

 badly preserved for the ornament to be detected. Dr. Rothpletz 

 says that "die durchweg abgeriebenen Flatten lassen ihre porose 

 Beschaffenheit zwar noch erkennen." They are, however, far 

 from presenting the curious appearance of U. schneideri, and on 

 the better-preserved portions no pores can be observed. Most of 

 the surface is irregularly worn and contains numerous holes. 

 These latter, however, are either due to some boring organism or 

 to the impression of hard particles in the matrix. Often the 

 hard particles, which may be grains of a dark mineral or frag- 

 ments of other fossil organisms, are still seen closely adherent to 

 the cup-plates, or even forced into them. 



Affinities of " H." piriformis. — Comparison of the analyses 

 shows at once that this species is not a Hypocrinus. The position 

 of the small infrabasal, the relations of the periproct to the pos- 

 terior basal and to the superjacent radials, and the modifications 

 of all the radials, are considerable distinctions. 



It is even doubtful whether the species should be referred to 

 the Gasterocomidfe, although it agrees with the diagnosis of 

 that Family, as given above, in all the known essential features 

 except in the shape of the radial facets. No other Gasterocomid, 

 however, has the infrabasals arranged in qinte the same wa3^ 

 These two points demand closer scrutiny. 



The position of the small infrabasal in the right posterior 

 radius is characteristic of Flexibilia Impinnata rather than of 

 Dicyclica Inadunata. When the latter forms have a. tripartite 



