NO. 2062. NEW ROTATORIA FROM PANAMA— BARRING. 531 



BRACHIONUS MIRABILIS Daday. 



A single specimen in a collection from the railroad bridge over 

 water in Black Swamp (1). 



PLATYIAS QUADRICORNIS (Ehrenberg), 



Noteus quadricornis Ehrenberg, Abh. Akad. Wiss. Berlin (for 1831), 1832, p. 143. 



The Isthmian form of this species has very long toes; the average 

 measurements of a considerable number of specimens from Wash- 

 ington are: Length of lorica Avithout anterior or posterior spines 225 

 fi, toes 37 fx; from Panama, lorica 217 //, toes 60 /i. In words, the 

 toes in the latter form are relatively nearly twice as long as in the 

 local form. There are no other important differences; the lorica in 

 the Panama specimens is less irregular in outUne, almost circular; 

 the posterior spines are similar, possibly a trifle longer, and the 

 points are identical ; the spines are very shghtly blmited at the extrem- 

 ity and end in a short, very fuie and needleUke point. The species 

 was found in the following collections: From railroad bridge over 

 water in Black Swamp (1), common; pool near railroad, between 

 Black Swamp and Gatun (2), few; pond at Miraflores (12), few. 



KERATELLA STIPITATA (Ehrenberg). 



Anuraea stipitata Ehrenberg, Infusionsth., 1838, p. 507, pi. 62, fig. 11. 



As this species is common here at Washmgton, the Panama material 

 was gone over carefully in order to determine the distribution of the 

 two closely related species K. stipitata and K. cocJdearis. AM the 

 Isthmian specimens belong to K. stipitata; K. cochlearis was not 

 found at all. The latter has been repeatedly recorded from South 

 America; it would be interestmg to know whether it is really 

 found there or whether the not very conspicuous difference in the 

 dorsal pattern has been overlooked. The distribution of the two 

 species in North and South America is still an unsolved problem; 

 personal observations indicate that Washington is on the border 

 line of the respective territories, but the evidence is too fragmentary 

 to warrant any definite conclusion. With all due respect to Doctor 

 Zelinka, the re (?) discoverer of this species, the writer beheves, until 

 confronted with the "corpus dehcti" from the neighborhood of 

 Berlin, that Lauterborn was correct in his opinion, that Ehrenberg 

 drew the quadrata ( = aculeata) — tesselation in the cocJdearis — outline. 

 This is not inexpHcable, as Ehrenberg does not record K. cocTilearis 

 at all. Now, it is well known, through the work of later investigators, 

 that this species is to be found nearly everywhere in Germany, and the 

 supposition is not unreasonable that Ehrenberg, finding a KerateUa 

 ( = Anurxa) with a median spine and a dorsal tesselation of some 

 sort, concluded without any careful examination that it was the, to 

 him, familiar quadrata pattern. In favor of this assumption is the 



