SHALLOW-WATER STARFISHES 299 



seven to nine, but often in a circle with one or two central on each 

 plate. They are short, thick, mostly angular, often three-sided, 

 mostly blunt, but many are acute and often beech-nut shaped. The 

 central one is frequently replaced by a short, thick, bivalved, or 

 sometimes trivalved, erect pedicellaria. In the larger specimen the 

 spinules are erect in a close, round cluster, leaving open intervals 

 between. In the other they are divergent, covering most of the 

 interspaces. The inner adambulacral spines form a nearly straight, 

 close row of three or four, which are nearly equal in length and 

 more or less angular and blunt; the middle row usually consists of 

 three or four similar but shorter spines in a curved or oblique series ; 

 outside of these, near the outer margin of the plate, are four to six 

 much shorter angular spinules in a curved group, like those on the 

 interradial plates. A bivalve pedicellaria sometimes replaces some 

 of these. In a few cases all the spinules, except those of the inner 

 row, form a circular, convergent group of about six nearly equal 

 spines. 



The dorsal parapaxillae are very regular, circular, or broad-ellipti- 

 cal, evenly covered with large, rounded granules. About twenty 

 to twenty-five granules form an outer circle on the larger plates; 

 inside these is a second circle, usually of eight to twelve somewhat 

 larger granules on the larger plates, or about six on the smaller 

 ones; the center is occupied by a single round granule of similar 

 size, or by two or three on the larger plates. Sometimes a small, 

 stout, erect bivalve pedicellaria occupies the center. Sometimes it 

 is one-third as broad as the plate. 



The marginal plates are evenly covered with close, rounded gran- 

 ules; the marginal ones are a little larger and divergent over the 

 margins, thus forming narrow covered channels between the plates. 

 Some of the marginals bear small bivalve pedicellariae, like those of 

 the dorsal plates. 



In one of these specimens the rays are considerably bent laterally, 

 and some of them are twisted and have the tips upturned, showing 

 more flexibility than the heavy plating would be expected to permit. 



Subfamily HIPPASTERIIN& Verrill. 



Hippasteriince VERRILL, Revision Genera, etc., in Trans. Conn. Acad., x, p. 



174, 1899. Fisher, op. cit., 19116, p. 223. 

 Antheneida (pars) PERKIER and others. 



This group includes stout, pentagonal or short-rayed starfishes, 

 that have large, elongated, divergent, and differentiated adambula- 

 cral spines, one or two larger ones situated on the central part of 



