552 Prodromus of the 



in closely approximated pairs,* so that the oral side of the 

 disc appears quadrate : pedicel monocamerous : tentacles 

 in groups on the end of each arm ; radial and transverse 

 development of each group equal : marginal anchors none : 

 genitals transversely folded bands which extend to the end 

 of the arms : muscles of the pedicel four, equidistant, pro- 

 jecting like ridges or pilasters f from the surface of the 

 camera : the principal muscles of the disc ligulate, each 

 one extending from the proximal end of a partition to the 

 end of an arm : marginal muscle ligulate, very thin at the 

 base of the tufts of tentacles : gelatiniform layer thin in 

 the disc, moderately thick in the pedicel. 



LUCERXARIA QUADRICORNIS. Miiller. 



Lucernaria quadricornis, Miill. Prod. Zool. Dan. 1776, p. 



227, No. 2754. 

 « «» Miill. Tegninger til Zool. Dan. 



Forste Haefte, Kiobenh. 1777, 



tab. XXXIX. Fide Fabr. 



Faun. Gronld. 1780, p. XVI. 



and 342. 

 " « Miill. Zool. Dan. 1788, Vol. I. 



p. 51, PI. 39, fig. 1-6. 

 «< «< Gmelin Linn. Syst. Nat. 1788, 



tom. 1, pars. VI. p. 3151. 



terized his genus, " Gclatinosum, nigosum, br.icliiatum," and refers to page 227 

 for the description of tlie species. L. quadricornis was the first and only species 

 ever described by Miiller, and therefore was the type, and must be retained as the 

 type of the herowitli restricted genus Lucernaria. 



* In all Lucernaria; the arms are more or less approximated toward the parti- 

 tions, probably because thereabouts are situated the more powerful muscles ; but 

 in this genus the approximation is not only close, but also evidently permanent, 

 and moreover the intcrtentacular sinuses opposite the partitions are only half as 

 deep as those which alternate with them. 



t These are altogether different from those in the pcdicellar camera of Calvado- 

 sia, in which the pilasters are totally devoid of muscular structure, and are com- 

 posed entirely of gelatiniform substance. 



