HlNDE. 



Radiolarian Chert. 



239 



in another (Fig. 7) some of the holes in the test are shown by sub- 

 circular spots .025 mm. in width. These oval forms are common 

 both at Angel Island and the Buri-buri Ridge. 



Genus, Ellipsidium, Haeckel. 



The tests are elliptical in outline, with numerous radial spines. 

 (Figs. 8, 9.) In one form (Fig. 8) the long diameter is .12 mm., 

 the wall .01 mm. in thickness, and the spines somewhat less in 

 length. In another (Fig. 9), the greater diameter is .27 mm. and 

 the spines .03 mm. in length. There are traces of the holes of the 

 test in this form. From Angel Island. 



Genus, Lithapium, Haickel. 



The tests are oval in outline, at one pole a stout radial spine. 

 (Figs, io, 11.) In one example (Fig. 10) the total length including 

 spine is .4 mm., length of spine .21 mm., breadth of test .14 mm. 

 In a smaller form (Fig. 11), with an incomplete spine, the long 

 diameter is .1 1 mm., and the shorter .085 mm. From Angel Island. 



Suborder, Discoidea, Haeckel. 

 Genus, Tripocyclia, Rust. 



The test is roughly triangular in outline; the sides are straight 

 or slightly curved ; from each angle a long, straight or partly curved 

 spine extends. (Figs. 12, 1 3 ) The diameter of the test is .15 mm.; 

 the spines range from .18 to .33 mm. in length. In general outline 

 this form resembles the Jurassic Tripocyclia trigonum, Riist,* which 

 has been also recorded by Dr. Parona from the Italian Jurassic of 

 Laveno and also in the Cesana schists. This form is not uncommon 

 at Angel Island, but it is seldom shown in the sections with the 

 spines complete. 



Genus, Hagiastrum, Haeckel. 

 Central portion of test subquadrate in outline; from each corner 

 there is a long, stout arm extending diagonally. (Fig. 14.) The 

 arms are apparently incomplete. No structure preserved beyond 

 traces of holes in one of the arms. Diameter of test .1 mm., length 

 of arms .2 mm. I have only seen a single specimen of this form, 

 which differs from the existing examples of the genus in the diag- 

 onal direction of the arms. Dr. Paronaf has, however, referred a 



*Pal;eontographica, Bd. XXXI, 1SS5, p. 293, PI. XXX, Fig. 3. 



t Atti. R. Accad. Scienze Torino, vol. XXVII, p. 15 (sep. copy), PI. Fig. 31. 



