WEST INDIAN STARFISHES 13 



The Forcipulosa, as the name implies, are specially character- 

 ized by the possession of forcipate pedicellariae, not found in 

 other orders. Two forms of pedicellariae are nearly always pres- 

 ent, except in the young. 



The minor or forcipulate pedicellarias, peculiar to this order, 

 generally form wreaths or large or small clusters on the spines, 

 but they may also occur, either singly or in clusters, on the in- 

 tegument of the dorsal or lateral plates, on the papular areas, and 

 in other situations. Their two blades are prolonged proximally 

 and crossed, -^dth muscles attached to the ends, so that they can 

 open and shut like forceps or scissors. Their valves are concave 

 and are usually armed with denticles. 



The major or forficulate pedicellarige are generally ovate or 

 lanceolate, sometimes wedge-shaped, stone-hammer-shaped, lyrate, 

 or spatulate. The tips may be acute, plain, flat or denticulate. 



They are mostly dermal, but may also occur on the ventral and 

 oral spines, or along the inner edges of the grooves, or attached 

 to pedicels in clusters within the grooves, or even on the pedicels 

 of the ambulacral feet. They may be of several sizes and forms 

 on one specimen. 



Certain species of Asteriidce, Coronaster, etc., have a peculiar 

 very large form of dermal pedicellarige, often as thick as the 

 spines, in which the broad valves terminate in a series of curved 

 denticles, so that when closed the valves resemble a pair of 

 clasped hands, or better still, a pair of clasped feet of a cat, with 

 the claws protruded. These may be called felipedal or unguicu- 

 late. (See pi. ix, fig. 4c.) 



This order now includes the following families and sub-families : 

 I. Family Asteriid^. 



Subfamilies Asteriin^ ; Stichasterin^ ; Pycnopodin^ ; 



Heliasterin^. 

 II. Family Zoroasterid^. 



III. Family Pedicellasterid^. 



IV. Family Brisingid^. 



Subfamilies Brisingin^; Labidiasterin^ (Type, Lab- 

 idiaster Lutk.) . 



families and sub-families of forcipulosa. 



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