SHALLOW- WATER STARFISHES 187 



more prominent carinals. The dorso-lateral plates are openly stellate- 

 reticulate, with rather narrow connective ossicles, leaving large angu- 

 lar papular areas with many papulae. Each plate bears one spine 

 on a raised central boss. 



Minor pedicellariae are very abundant between and around the 

 bases of the spines. Marginal and adambulacral spines are nearly 

 as in the type. No peractinal plates are visible. The specimen is 

 dry and varnished. It was stained dark purple to imitate the natural 

 color. 



British Columbia (Geological Survey of Canada, No. 19). 



Genus Urasterias Verrill. 



Plate LXX, figures 1-4. 

 Urasterias VERRILL, Amer. Journ. Sci., xxvin, p. 67, 1909. Type, U. linckii 



(M. andT.). 



Large starfishes with a loose, openly reticulated dorsal skeleton, 

 composed largely of slender ossicles, with few larger plates, mainly 

 in the interradial or genital areas. Dorsal spines large, mostly iso- 

 lated on the plates; median radial row usually distinct; elsewhere 

 they are mostly scattered. Superomarginal spines elongated, mostly 

 standing in single rows. No notable actinal plates nor spines. Adam- 

 bulacral plates diplacanthid or subdiplacanthid. 



Some details of the type are figured on pi. LXX, figs. 1-4. 



Genus Parasterias Verrill, nov. See also p. 53. 



Type, P. albertensis Ver. 



Dorsal and marginal skeleton fairly well developed, reticulated 

 nearly as in typical Asterias. Interactinal plates lacking or rudi- 

 mentary, not showing externally. Adambulacral plates diplacanthid. 



PARASTERIAS ALBERTENSIS Verrill, sp. nov. 

 Plate LVII, figures I, 2 ; plate LXX, figure 6. 



A five-rayed species with rather depressed rays and openly reticu- 

 late structure, the dorsal ossicles being thin and weak, while the 

 papular areas are large and conspicuous. Dorsal spines are not 

 numerous, very small, tapered, obtuse, not capitate, pretty evenly 

 distributed on the ossicles, standing singly and not forming a con- 

 spicuous median row. 



Madreporite rather large, convex, fine-grained, not encircled by 

 spines. Minute major pedicellariae, acute-ovate in form, are 



