. Bulletin - United States National Museum. Science. REVISION OF PALEOZOIC STELLEROIDEA. 225 Original description.—'' (Order Ophiuridae. Family Euryales.) Body circular, covered with squamiform plates; genital openings in the angles of junction of the arms beneath; arms (simple) formed of alternating ; Oenoholotype.—''Species Unica. Protaster sedgwickii. ; Original description of P. sedgwiclii.—''The disk is circular, and shaped like that of an Ophiura. The arms are five in number, very narrow, equidistant, and sunilar. "The upper and under surfaces of the disk w
. Bulletin - United States National Museum. Science. REVISION OF PALEOZOIC STELLEROIDEA. 225 Original description.—'' (Order Ophiuridae. Family Euryales.) Body circular, covered with squamiform plates; genital openings in the angles of junction of the arms beneath; arms (simple) formed of alternating ; Oenoholotype.—''Species Unica. Protaster sedgwickii. ; Original description of P. sedgwiclii.—''The disk is circular, and shaped like that of an Ophiura. The arms are five in number, very narrow, equidistant, and sunilar. "The upper and under surfaces of the disk were covered by small, similar, more or less regular, polygonal or crescentic plates, imbri- cated in scale-fashion, and having punctated surfaces. Those of the under side of the body are smaller and more regular than those of the upper. The mouth is cen- tral, and rather small in proportion to the disk. The buccal ap- paratus is composed of ten parts or proc- esses, arranged in pail's; half of each springs from the origin of each arm in a diverging manner, and meets the corre- spondinghalf to form a lanceolate tooth-. FlG. !2.—Oral skeleton of Paljeura neglecta, much enlarged, AFTER Jaekel. a, ambulacralia; od, adambulacralla. like projection, deeply indenting the cavity of the mouth. Of how many separate ossicles each of the buccal processes was composed the specimen affords but very indis- tinct indication. They seem to affect a slightly falcate form at their extremities. The arms were composed of alternating, somewhat quadrate ossicula, the sides of which were deeply indented supe- riorly, in order to form spinifcrous crests. The spines were appar- ently short, and not equal in length to the length of an ossicle, obtuse, and few in a row. The under surfaces of the brachial ossicula were not indented laterally. The central portions of the u])i)cr surfaces of the brachial ossicles were hollowed out slightly, and the sutures between them deeply impressed. About 12 of th
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