84 BULLETIN 82, UNITED STATES NATIONAL MUSEUM. 



Dorsal surface. — Of the radial pentagon, tlio surface wliich is covered by the cen- 



trodorsal (see fig. 12, p. G5). 

 Dorsal tip. — Of centrodorsal; that portion of the ccntrodorsal, surrounding the bare 



dorsal polo, wliich bears the so-called small mature cirri (see fig. 310, p. 269). 

 Dorsal transverse ridge. — A transverse ridge found on the outer cirrus segments; 



tliis structure is only developed in a few species, where it takes the place of 



<Ioisal spines (see figs. 349, 352, p. 291). 

 Dorsal tubercles. — Tubercular processes developed on the dorsal side of the outer 



segments of the cirri; they may be described as short and blunt dorsal spines; 



as with the latter there is ordinarily only one to each cirrus segment, though 



sometimes two or even tliree are found side by side (see figs. 346, p. 289, and 



370, p. 299). 

 Dorsocentral. — The terminal stem plate of the stalked comatulid larva; the primi- 

 tive dorsal central plate; tliis term is sometimes used instead of centrodorsal 



(see figs. 2, p. 61, 532-540, pi. 3). 

 Dorsolateral processes. — The produced dorsolateral borders of tlio ossicles of the 



di\-ision series and of the first two bracliials, as seen in Poecilometra. 

 Uorsoventral axis. — See Axis 2. 



E. 



Einhryonic basals. — Basals which appear as true basals only in the young, in the 



adult becoming metamorphosed into a rosette. 



Among the comatuUds true basals are found onl}' in the Atelecrinldae, 



but embryonic basals occur in the species of all the other families. 

 Endocyclic. — With the mouth situated approximately in the center of the coil of the 



digestive tube, and therefore approximately in the center of the disk (see figs. 



20, 22-24, p. 69, and pp. 110, 111). 



Tliis includes all of the comatuLids except those belonging to the family 



ComasteridsB and Uintacrinidw. 

 Entire disk. — A disk in which the free borders of the intcrambulacral areas are 



straight or slightly convex (see figs. 15-19, p. 67). 

 Entire regeneration. — See Regeneration B 1. 

 Entrochi. — A series of trochitffi joined together as m life; a section of a stem or 



column. 

 Epizygal. — The dLstal segment of a syzygial pair. 

 Exocyclic. — With the mouth situated on the border of or outside of the coil made by 



the digestive tube, and therefore marginal or submarginal on the disk (see 



figs. 21, 25-28, p. 69, and pp. 110, 111). 



This includes most of the species included in the faiuily Coinasteridje, 



and the species of the Uintacrinidfe. 

 External arm. — The external arms are the two lying on the outer si<les m reference 



to the IBr scries; more rarely the reference is to the IIBr scries, but in this case 



the fact that the second division series is the determining series is always 



mentioned (sec figs. 61&, p. 87, and 78, p. 131). 



