NO. 2164. REVISION OF ROTATORIAN OENERA—HARRING. 557 



sensory pit on the foot has been observed. The toes are nearly one- 

 third the length of the lorica, slender, and almost straight ; they taper 

 gradually to very fine points. 



Total length, 128 m; length of lorica, 86 fx, width, 54 ju; width of an- 

 terior margin, 29 m; depth of ventral sinus, 18 ^t; length of foot 

 groove, 25 /x, width, 15 m; length of foot, 32 ju, of last joint, 18 /x; 

 length of toes, 27 fx; depth of body, 39 fx. 



Type.— C&t. No. 16586, U.S.N.M., was collected at Kenilworth, 

 District of Columbia; on the Isthmus of Panama it was collected by 

 Dr. C. Dwight Marsh at Empire and in Rio Trinidad, at Escoval. 

 Dr. Chancey Juday, of the University of Wisconsin, collected this 

 species at Puerto Barrios, Guatemala. It appears to be a rare ani- 

 mal, only a few specimens occurring in each of the collections men- 

 tioned. 



18. LEPADELLA RHOMBOIDES (Gosse). 

 Plate 95, figs. 12-15. 



Metopidia rhomboides Gosse, Hudson and Gosse, Rotifera, 1886, vol. 2, p. 108, pi. 

 25, fig. 10.— WiERZEJSKi, Rozpr. Akad. Umiejetn., Wydz. Mat.-Przyr., ser. 2, 

 vol. 4, 1893, p. 246, pi. 6, fig. 46.—? Skorikov, Trav. Soc. Nat. Kharkow, 

 vol. 30, 1896, p. 328.— Lie-Pettersen, Bergens Mus. Aarb. (for 1909), 1910, 

 No. 15, p. 70. — Lucks, Rotatorienfauna Westpreussens, 1912, p. 123, text 

 fig. — Murray, Journ. Roy. Micr. Soc, 1913, p. 459. 



Lepadella rhomboides Harring, Bull. 81 U. S. Nat. Mus., 1913, p. 65. 



The lorica is rhomboid-ovate in outline; its width is about two- 

 thirds of the length. The dorsal plate is moderately convex, with a 

 very wide and moderately high keel, beginning at the anterior margin 

 and continuing to the end of the lorica. The sides of the keel are 

 strongly convex and meet at an obtuse angle, thus forming a faint 

 median ridge. The ventral plate is shghtly concave. The entire 

 surface of the lorica is covered with a "moire" pattern of short, 

 nearly straight and parallel lines or minute wrinkles. The cross sec- 

 tion of the body is moderately triradiate, as shown in figure 15; the 

 width of the keel is a little less than one-third the width of the dorsal 

 plate; the dorso-ventral depth of the body is nearly one-third the 

 length of the lorica. 



The anterior margin is rather narrow, its width being only one- 

 fourth the length of the lorica. The dorsal sinus is broadly U-shaped 

 with a small median notch ; its depth is one-third of the width. The 

 ventral sinus is V-shaped and pointed posteriorly; the depth is two- 

 thirds of the width of the anterior margin. No collar is present on 

 either the dorsal or the ventral plate. 



The foot groove is U-shaped and quite narrow, rounded anteriorly 

 and with parallel sides; its length is a little less than one-third the 

 length of the body, and the width is equal to one-half its length. 

 The lorica is rounded posteriorly, without any emargination. 



