498 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxxvi. 



4. COMACTINIA, new genus. 



1840. Comatiihi (part) J. Muller, Areliiv fiir Naturgeseli., 1840, I, p. 311. 



1841. Alccto (part) J. ]\[iJLLER, Archiv fiir Natiugesch., 1841, I, p. 143. 

 1849. Votnatiila (Alccto) J. MiJLLEK, Abbandl. d. k. preuss. Akad., 1847, p- 



250. 

 1878. Anicdon (part) Pouktales, Bull. Mus. Comp. Zool., V, p. 214. 

 1881. Actiiiomctra (part) P. H. Carpenter, Bull. Mus. Comp. Zool., IX, No. 



4, p. 1.54. 

 1908. Comasicr (part) A. H. Clark, Proc. U. S. Nat. Mus., XXXIII, p. 685. 

 1908. Phonogcnia (part) A. H. Clark, Proc. U. S. Nat. Mus., XXXV, p. 124. 



Genotype. — Alecto echinoftera J. Miiller, 1841. 



Description. — Centro-dorsal rather large, discoidal, the cirri ar- 

 ranged in a single marginal row. 



Cirri short and stout, IX-XXVII, 8-12; basal joints short, then 

 tAvo or three half again to twice as long as broad, the following de- 

 creasing in length, being about as long as broad distally; opposing 

 spine, small, erect, median in position; no dorsal spines or projec- 

 tions; terminal claAv abont as long as the antepenultimate joint 

 (Avliich is longer than the j^enultimate) stout and strongly curved 

 basally, becoming slender and nearly straight distally. 



Ends of the basal rays visible in the interradial angles; radials 

 concealed; IBr^ very short and l)and-like, closely united laterally; 

 IBro (ax) triangular, usually about twice as broad as long; TBr^ and 

 first two brachials in lateral contact, though not laterally flattened. 



Ten arms; proximal l)rachials discoidal, or oblong, then becoming 

 triangular, at first broader than long, later about as long as broad, 

 and wedge-shajxMl terminally. 



Oral ])innules longer than, but not quite so stout as, those succeed- 

 ing; middle pinnules with more or less developed spinous edges and 

 dorsal processes on the joints. 



Distiihiition. — Caribbean Sea, northward to South Carolina and 

 southward to Brazil. 



Depth. — Sublittoral, and down to 202 fathoms. 



S. LEPTONEMASTER, new genus. 



Genotype. — Leptonemaster venustus^ new species. 



Description. — Centro-dorsal a thin flat disk; cirrus sockets in a 

 single marginal row. 



Cirri XV-XX, 12-15, long and slender; first joint short, second 

 half again as broad as long to nearly square, third about twice as 

 long as its terminal diameter, fourth the longest, two and one-half 

 to three times as long as its proximal diameter, fifth a transition 

 joint, not quite so long as the fourth, with a dark band about its 

 center; following joints gradually decreasing in length, the antepe- 

 nultimate being very slightly longer than broad, or squarish, and the 



