550 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.51. 



asymmetric. The right toe tapers rapidly for half its length and 

 ends in a slender, nearly cylindrical point. The left toe tapers 

 gradually to the point and is strongly decurved. The last joint of 

 the foot is twisted, so that the curved left toe is almost directly 

 under the right toe. 



Total length, 98 n; length of lorica, 70 fj., width, 56 m; width of 

 anterior margin, 24 fi; depth of ventral sinus, 19 m; length of foot 

 groove, 17 At, posterior width, 15 ju; length of foot, 26 n, of second 

 foot joint, 11 ju; length of right toe, 16 ix; depth of body, 29 /x. 



Type. — Cat. No. 16585, U.S.N.M., was collected in Camacho Res- 

 ervoir, on the Isthmus of Panama. This species occurs rather 

 widely distributed on the Isthmus, but usually in small numbers. 

 It has been found by the writer in Lake Smith, near Norfolk, Vir- 

 ginia, and in collections made by Dr. E. A. Birge, of the University 

 of Wisconsin, in Rondeau Harbor, Ontario, on the Canadian shore 

 of Lake Erie, and in ponds in Audubon Park, New Orleans, Louis- 

 iana. 



12. LEPADELLA BIDENTATA Voronkov. 



Plate 91, fig. 6. 



Lepadella dactyliseta bidentata Voronkov, Trudy Hidrobiol. Slants. Glubokom 



Oz., vol. 5, pt. 1, 1913, pp. 99, 107, text fig. 

 Metopidia dactyliseta bidentata Voronkov, Trudy Dnieprovsk. Biol. Stants., pt. 



2, No. 5, 1915, p. 71, text fig. 



This species has not been studied by the writer. The figure is 

 redrawn from the original by Voronkov, which shows an animal 

 with marked differences from Lepadella dactyliseta (Stenroos) and 

 evidently entitled to specific rank. 



The original description is not very detailed, but the figure shows 

 the lorica to be broadly oval and without any dorsal sinus. The 

 ventral sinus is very deep, rounded posteriorly, and fairly wide 

 anteriorly. The posterior end of the lorica has a small, rounded 

 median lobe and, separated from this by shallow emarginations, 

 two small spines. The toes are straight and paraUel-sided for one- 

 half their length and taper somewhat abruptly to slender points. 

 No measurements are given in the text. 



Voronkov found three specimens in the Desenka, a tributary to 

 the Dniepr, near Kiev, Russia. 



13. LEPADELLA BOREALIS, new species. 



Plate 92, figs. 13-16. 



The lorica is usually pyriform in outline and obtusely pointed 

 posteriorly, but may be sUghtly constricted in the region of the 

 lateral antennae, as shown in figure 14. The dorsal plate is evenly 

 rounded and moderately convex; the ventral plate is shghtly con- 



