75 NATURAL HISTORY BULLETIN. 



is another similar species. It differs in having the proximal 

 arm-spines, short, stout, obtuse, slightly bent, six or seven at 

 the tenth joint, the length increasing gradually from the low- 

 est to the upper ones, but showing no marked difference in 

 length, even between the first and second. 



Family, ASTROSCHEMID^, nov. 



Arms simple, long, slender, coiled. Disk five-lobed, with 

 ten radial ribs; naked or granulated. Radial shields narrow, 

 usually elongated. 



Teeth large, stout, several in a vertical row. Mouth-pa- 

 pillae small or wanting. 



Under arm-plates small. Upper arm-plates poorly devel- 

 oped, often wanting, sometimes represented by two or more 

 pieces, covered by naked skin or granulated. 



Side arm-plates relatively large, covering a large part of 

 the lower side of the arm, and usually bearing two elongated 

 spines or tentacle-scales. 



Oral and adoral plates regularly formed, but covered by 

 cuticle. 



Genital slits short, situated near the outer margin of the 

 disk. 



Mouth-frames strong, well developed, but without wing- 

 like processes. 



This family includes Astroschema, Astrocreas, and Ophio- 

 creas. 



Astroschema oligactes Liitken. 



Asterias oligactes Pallas, Acad. Caes. Leop. Nova. Acta., II, p. 239, 

 pi. VI, fig. 23. 



Astroschema oligactes Lutken, Vid. Meddel., p. 16, 1856; Add. ad. 

 Hist. Oph., Pt. II, p. 155, pi. V, fig. 3. Duj. & Hupe, Hist. Nat. 

 Zooph. Echin., p. 297, 1862. Lyman, 111. Cat. Mus. Comp. Zool., 

 VIII, Pt. II, p. 62. Verrill, Trans. Conn. Acad., I, p. 341. Lyman, 

 Report Voy. Challenger, Zool., Ophiuroidea, V, p. 278, pi. XLIV, 

 figs. 1-5, 1882, anatomy; Bull. Mus. Comp. Zool., X, p. 280. 



Ophiocreas, sp., Nutting, Narrative, p. 80. 



