NO. 2062. NEW ROTATORIA FROM PANAMA— EARRING. 547 



MONOSTYLA PYRIFORMIS Daday. 



Monostyla truncata Murray, Joum. Royal Micr. Soc, 1913, p. 358, pi. 15, fig. 38. 



Partly contracted specimens agree perfectly with Daday's figure, 

 whUe the fully contracted material corresponds with Murray's. 

 The name given by Daday is used here, in preference to Turner's; 

 while the possibility that they may be the same species is not excluded, 

 positive evidence is lacking. M. truncata Turner is here listed as a 

 probable synonym of M. closterocerca Schmarda. It seems to the 

 writer madvisable to simply "use up" the names given in the past 

 without sufiicient description to enable one to form any defhiite 

 opinion as to the identity of the animal actually before the original 

 observer, as such "resurrections of the dead" tend to befog the 

 question of distribution. If we use Turner's name for this South 

 American species, it wiU of course figure in all lists as being common 

 to both North and South America. That such is reaUy the case is 

 very doubtful; M. pyriformis was described by Daday from Para- 

 guay, Murray found it in Brazil, and it is not rare on the Isthmus. 

 Taken together, this indicates that the species is common and widely 

 distributed in South America. To give it an " all- American " dis- 

 tribution merely on the strength of Turner's unrecognizable figure is 

 unwarranted and misleading in the face of an abundance of pre- 

 sumptive evidence that the species of the genera Lecane and Mono- 

 styla usually have a rather circumscribed distribution. 



This species occui-s : In a pool near the railroad, between Black 

 Swamp and Gatun (2), few; creek flowing into Camacho Reservoir 

 (3), few; stagnant pool at Empire (4), few; Rio Grande Reservoir 

 (5), common; Rio Grande (6), rare; Rio Trinidad, about 1 mUe 

 from mouth (9), rare; above Agua Clara (10), rare. 



MONOSTYLA BULLA Gosse. 



In a pool near the railroad, between Black Swamp and Gatun (2), 

 common; sluggish stream in savannas between Panama and Old 

 Panama, few; Gatun Lake, few; creek flowing into Camacho Reser- 

 voir (3), abundant; Rio Cocoli, above lake, few; stagnant pool at 

 Empire (4), abundant; Rio Grande Resei-voir (5), common; Rio 

 Grande (6), few; pond east of Canal at Empire (8), few; Rio Trinidad, 

 above Agua Clara (10), abundant. 



MONOSTYLA QUADRIDENTATA Ehrenberg. 



This species was found only in the following collections : Stagnant 

 pool at Empire (4), common; Rio Grande Reservoir (5), few; Rio 

 Trinidad, above Agua Clara (10), few. 



