NO. 2062. NEW ROTATORIA FROM PANAMA— EARRING. 535 



LECANE SIBINA, new species, 

 Plate 23, figs. 5-7. 



The body is broadly ovate and its thickness more than two-thirds 

 of the mdth. The anterior margins are very nearly coincident and 

 slightly concave, with two lateral triangular projections, but without 

 true spines. The dorsal plate is very broad and ovate in outline; 

 while mthout any facetting whatever, it has two deep anterior, 

 diverging folds, the limits of a strongly convex lobe. At the sides of 

 this lobe the dorsal plate is concave, making it possible for the ante- 

 rior dorsal and ventral margins to meet and close the lorica when 

 the head is retracted. The ventral plate is shghtly narrower than 

 the dorsal, oval and without facetting; some inconspicuous trans- 

 verse folds are present near the posterior end; the anterior margin has 

 a very small median sinus. The lateral sulci are moderately deep 

 and do not reach the anterior margin; they are indicated by dotted 

 lines in figure 7. The posterior segment of the body is very large 

 and prominent, projecting quite a distance over the toes; it is notice- 

 ably emarginate at the outer angles of the coxal plates, which are 

 large and obtusely triangular. The first foot joint is minute, the 

 second short and broad. The toes are in dorsal view nearly parallel- 

 sided, a trifle narrowed immediately beyond the base and widest at 

 the beginning of the posterior third, where there are some obscure 

 annular constrictions. The claw is haK the length of the toe, un- 

 usually slender, conical, and very shghtly decurved. At its base there 

 is a small spine, separated from the claw by a deep notch. 



Total length, 200 /*; length of lorica, 165 /x; length of dorsal plate, 

 130 /ji, width, 125 /x; width of anterior points, 78 /x; width of ventral 

 plate, 116 /x; length of toe without claw, 42 /x, claw, 20 /x; depth of 

 body, 93 /x. 



Type.— Cat. No. 16582, from a stagnant pool at Empire. It is not 

 common. 



This species has considerable resemblance to Lecane ungulata 

 (Gosse). The latter is not as thick at L. sihina, and the body is 

 relatively longer; its absolute dimensions are also considerably 

 greater and the anterior margins are not coincident, the dorsal being 

 nearly straight, while the ventral margin has a deep sinus. 



LECANE UNGULATA (Gosse). 

 Caihypna ungulata Gosse, Joum. Royal Micr. Soc, 1887, p. 361, pi. 8, fig. 1. 

 A single specimen from a pool near the railroad, between Black 

 Swamp and Gatun (2). 



LECANE CURVICORNIS (Murray). 



Caihypna curvicornisMvRRAY, Joum. Royal Micr. Soc, 1913, p. 346, pi. 14, fig. 22. 



? Cathypna nitida Murray, Joum. Royal Micr. Soc, 1913, p. 347, pi. 14, fig. 24. 



Cathypna lofuana Murray, Joum. Royal Micr. Soc, 1913, p. 551, pi. 22, fig. 1. 



Apparently these three names designate one and the same species. 



A specimen labeled Cathypna curvicomis was given me by Mr. Murray; 



