576 BULLETIN 82, UNITED STATES NATIONAL MUSEUM 



COMANTHUS SOLASTER (A. H. Clark) 



Plate 20, Figure 51 

 [See also vol. 1, pt. 1, fig. 81 (dorsal view), p. 134] 



Comatula solaster A. H. Claek, Proc. U. S. Nat. Mus., vol. 33, 1907, p. 153 (description; Albatross 



Sta. 4944). 

 Comaster solaster A. H. Clark, Proc. U. S. Nat. Mus., vol. 33, 1908, p. 686 (listed); vol. 34, 1908, 



p. 317 (Japan). 

 Phanogenia solaster A. H. Clark, Proc. U. S. Nat. Mus., vol. 35, 1908, p. 124 (listed). 

 Comanlhus solaster A. H. Clark, Zool. Anzeiger, vol. 34, No. 11-12, 1909, p. 366 (listed); Crinoids 



of the Indian Ocean, 1912, p. 94 (synonymy; range); Proc. Biol. Soc. Washington, vol. 26, 



1913, p. 178 (range in east Asia); Unstalked Crinoids of the Siboga Exped., 1918, p. 49 (in key; 



range). 

 Comanlhus (Comanthus) solaster A. H. Clark, Vidensk. Medd. fra den naturhist. Forening i K0ben- 



havn, 1909, p. 147 (Formosa Channel, 35 fathoms). 

 Comanthus (Bennetlia) solaster A. H. Clark, Journ. Washington Acad. Sci., vol. 5, No. 6, 1915, 



p. 214 (southern Japanese species; range and its significance). 



Diagnostic features. — With its very broad and dorsally flattened division series 

 which are in close lateral contact, and its numerous undeveloped cirri, this species 

 has more the appearance of a species of Comanthina than that of any of the other 

 forms in the genus Comanthus. 



The longest cutI have 18-30 (rarely more than 25 and usually about 20) segments, 

 and the arms, which -are short, stout, broad at the base and rapidly tapering, are 

 15-36 (usually about 20) in number, and from 80 to 90 mm. in length. 



Description. — The centrodorsal is large, discoidal, with the bare polar area 

 flat, 6 mm. in diameter. The cirrus sockets are arranged in a single marginal row. 



The cirri are XV-XXV (usually about XX), 18-23 (rarely as many as 30), 

 20 mm. long, resembling those of C. japonica but slightly less stout. 



The radials and most or all of the IBri are concealed by the centrodorsal. The 

 IBr2 (axillaries) are triangular, twice as broad as long or even broader. The IIBr 

 series are 4 (3 + 4). The IIIBr series are 4 (3 + 4), but are not developed in the 

 entire series. The division series are more or less flattened dorsally and are broad 

 and in close lateral apposition, being separated only very slightly by the dorsal 

 carination of Pd- 



The arms are 15-30 in number, from 80 to 90 mm. long, comparatively stout, 

 especially in the basal portion. The first 2 brachials are rather large, subequal, 

 slightly wedge-shaped, about twice as broad as long exteriorly. The first syzj'gial 

 pair (composed of brachials 3 + 4) is oblong, from half again to twice as broad as 

 long. The next 3 brachials are oblong, two and one-half times as broad as long, 

 and those following become tjiangular, half again as broad as long, and short wedge- 

 shaped in the distal half of the arm. From about the fourth onward the brachials 

 have rather prominent distal edges. 



Syzygies occur between brachials 3 + 4, again from between brachials 11 + 12 to 

 between brachials 20 + 21, and distally at intervals of 4 or 5 (usuaUy 4) muscular 

 articulations. 



The disk is 20 mm. in diameter, and bears a few scattered calcareous granules 

 in the anal area. The mouth is marginal, radial, or interradial. The anal tube is 

 very large and centrally situated. 



