NO. 2062. yEW ROTATORIA FROM PANAMA— HARRIXO. 553 



DIURELLA TENUIOR (Gosse). 



From Rio Trinidad, at Escoval (11), few. 



DIURELLA DIXON-NUTTALLI Jennings. 



From a pond at Miraflores, back water of Rio Camitillo (12), few, 



POLYARTHRA TRIGLA Ehrenberg. 



Polyarthra platyptera Ehrenberg, Infusionsth., 1838, p. 441, pi. 54, fig. 3. 

 In Gatun Reservoir, few; Camacho Reservoir, few; Rio Grande 

 Reservoir (5), common; Carabali (Gorgona) Reservoir, few; Rio 

 Trinidad, at Escoval (11), few; pond at Miraflores, back water of 

 Rio Camitillo (12), common. 



ASPLANCHNA BRIGHTWELLII Gosse. 



Isthmian specimens from both locahties have trophi of a pro- 

 nounced amphora type,^ with a strongly developed inner tooth on 

 the rami. It is improbable that this is of any special significance; 

 in a pond at Fourmile Run, near Washington, where this species is 

 abundant, aU the material collected in 1913 had the amphora type 

 of trophi, while this year the normal Irightwellii type, without the 

 inner tooth, is the only one found. It should be explained that the 

 character of this pond has changed; last year it was without any 

 fixed vegetation and the fauna practically hmnetic in its composition. 

 This year there is an abundance of vegetation, mainly Potamogeton 

 crispum, which in places forms large tangled masses, and the fauna 

 is now a characteristic stagnant-pond fauna. 



This species occurred in a stagnant stream under the old bridge, 

 Old Panama, probably Rio Alcorobo, common; Gatun Lake, 

 abundant. 



TESTUDINELLA INCISA (Temetz). 

 Pterodina indsa Ternetz, Rot. Umg. Easels, 1892, pp. 20, 41, pi. 3, figs. 19, 20. 

 In creek flowing into Camacho Reservoir (3), few; Rio Trinidad, 

 above Agua Clara (10), rare. 



? TESTUDINELLA TRILOBATA (Anderson and Shephard). 



Pterodina trilobata Anderson and Shephard, Proc. Royal Soc. Victoria, vol. 4, 

 1892, p. 79, pi. 12, fig. 7. 



Among material collected from the railroad bridge over Black 

 Swamp (1) a single specimen of a very large Testudinella occurred. 

 It corresponds closely with the figure in Kirkman's paper ^ with one 

 exception, the median lobe of the anterior dorsal margin is produced 

 as a long, slender spine. The length of the lorica, measured from 



1 Compare Powers, A case of polymorphism in Asplanchna simulating a mutation. Amer. Nat., New 

 York, vol. 4G, 1912, pp. 441-462, 526-552. 

 8 Kirkman, Th., List of some of the Rotifera of Natal. Joum. Royal Micr. Soc., 1901, pp. 229-241, pi. 6. 



