

sm 



im 



D 



Figure 4. — Some morphological charaoteristies used in identification of asteroids (somewhat schematic). A. Aboral 

 and oral sides of a startish U-l<lo>ita.stei- hi.'ipi(lu-'<) . B. PoUia, without (a) and with ( Ij ) sucker. C. I'edicellaria. 

 crossed (c) ; straight (d) ; and bivalve (e). D. Arm in cross .section, showing ossicles. E. Radii, ab, ad, al — 

 anibulacral, adambulaeral, and actinolateral ossicles; im, inferomarginal plates; m, madreporite; p, paxillae; R. 

 long radius ; r, short radius ; s, spines : sm, superomarginal plates ; ts, tooth spine. 



Cribrlfo)"m organ: Vertical depression between 



adjacent marginals, lined with a series of thin 



vertical platas (lamellae). 

 Disc: Body of starfish, exclusive of arms. 

 Epiproctal cone: A sharp dermal elevation in the 



center of the aboral surface of certain starfish. 

 Fasciolated: Banded with small spinules, or 



ciliated. 

 FeMped pedicellarht : Straight pedicellaria with 



overlapping- claws resembling a cat's forepaws 



when faced together. 



Furrow: Groove running between adjacent seines 



of plates. 

 Granule: Small grain. 

 Hyaline : Clear, glassy. 

 Imbricate : Overlapping. 



Inferomargimd : Plate in lower marginal series. 

 Interradial: Between arms. 

 Lamella: Thin vertical platelet. 



Lateral: Along 

 abactinal. 



sides, between actinal and 



134 



U.S. PISH AND WILDLIFE SERVICE 



