406 MEMOIRS OF THE UNIVERSITY OF CALIFORNIA 



CoarPARisoxs. — Pavillardia tentacuUfera differs from Gymnodinium pseudo- 

 nocfUuca Poucliet (1892&) in being smaller, 58," instead of 110/^ in length, in 

 having a brown instead of a colorless tentacle and in shape and location of the 

 girdle. This is farther anterior and more strongly deflected posteriorly on 

 both ends in Ponchet's species, and in the distal end only in P. tentacidifera. 

 Furthermore the epicone is relatively much smaller than the hypocone in his 

 species than it is in the one here described. It shares with this species the 

 tendency of the distal end of the girdle to be strongly deflected posteriorly, and 

 to be reduced nearly to ol)literation distally. In this respect they both show 

 eai'lier stages in a degeneration process (or possibly earlier ones in a develop- 

 ment one) which progresses still farther in Protodinifer and Noctiluca. 



The general form of the body, the structure of the girdle and the tendency 

 to striation recall conditions in Gyrodinium, especially in species close to 

 Gymnodinium in the matter of degree of displacement of the girdle. 



It is possible that Ponchet's (1892&) Gymnodinium pseudonoctiluca should 

 be transferred to this family, though hardly to the genus Pavillardia. Its 

 "tentacle" appears to be more like a lateral sulcal pseudopodium and much less 

 like a median tentacle such as those of NoctiJuca and PavillanUa. Pending- 

 fuller knowledge of such pseudopodia in Gymnodiuiinn it seems wise to leave 

 Ponchet's species in that genus. 



NOCTILUCA Sur 



irav 



Not "Noctiluca marina" Adler (1852"). Not binomial. Annelid. 



Not "Noctiluca marina" Linnaeus (1758), p. 654, synonym of Nereis noctiluca; nor 



"Noctiluca marina" Linnaeus (1764), pp. 3, 203, reprint by Adler. Ed. 3 in 1787. 



Annelid. 

 "Medusa marina" Slabber (1771, fide Ehrenberg, 1834 for date), p. 67, pi. 8, figs. 4, 5; 



not binomial name. Also edition dated 1778. 

 f Nereis noctiluca Miiller, 0. F. (1776), p. 217, in part. 

 Gleha Bruguiere (1791), pi. 89, figs. 2, 3. 



Medusa scintillans Macartney (1810), pp. 264-265, pi. 15, figs. 9-12. 

 SlaUeria Oken (1815). 



Noctiluca miliaris Suriray Mss, Lamarck (1816), pp. 470--472. 

 Mammaria scintillans. Ehrenberg (1834), p. 559. 



fPhysematium atlanticum, Meyen (1834), p. 163, fide Ehrenberg (1834), p. 522. 

 Noctiluca miliaris Suriray (1836), pp. 1-16, pis. 1-2. 



DiAGXOSIS 



The body is inflated .subrenif orm to spheroidal ; distinction between epicone 

 and hypocone obliterated, in the adult, by loss of girdle resulting from inflation 

 by hydrostatic vacuoles. Sulcus deeply reentrant, the medium cytostomal 

 region extended anteriorly in the straight apical trough, girdle represented 

 only by its proximal remnant ; longitudinal flagellmn short, transverse flagellum 

 reduced to a projecting mobile tooth ; tentacle at posterior end of sulcus ; cyto- 

 plasm vacuolated, anastomosing mobile strands move from periphery to central 

 mass containing nucleus ; colorless or bluish green, sometimes tinged with yellow 



