548 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. 51. 



the posterior end of the lorica, which is squarely truncate or very 

 shghtly emarginate. 



The foot is one-fourth the length of the lorica and quite stout; 

 its three joints are of approximately equal length. The toes are one- 

 tliird the length of the lorica and taper rather rapidly for one-half 

 their length, ending in long, slender points. 



Total length, 127 m; length of lorica, 90 ju, width, 60 m; width of 

 head opening, 30 ^u; depth of ventral sinus, 17 n; length of foot 

 groove, 24 fx, anterior width, 15 fi, posterior width, 12 n; length of 

 toes, 32 n; depth of body, 38 fjt. 



A few specimens of this species have been found by the writer in 

 Lake Smith, the source of the water supply of the city of Norfolk, 

 Virginia. It does not appear to have been recorded by anybody but 

 Stenroos and Lucks, so that it is probably rare; wliile without any 

 striking peculiarities, it is yet a fairly well marked species and it 

 is not likely to have been overlooked. 



10. LEPADELLA BENJAMINI, new species. 



Plate 93, figs. 1-8. 



The form of the lorica varies from subcircular to broadly ovate; 

 the extremes are shown in figures 1 and 2. The dorsal plate is 

 evenly and very strongly arched; its edges project considerably 

 below the general level of the nearly flat ventral plate; posteriorly 

 it is slightly emarginate over the foot groove. Tlie width of the 

 body varies from three-fourths to seven-eighths of the length of the 

 lorica. The cross section of the body is approximately semicircular; 

 its dorso-ventral depth is more than half the width of the lorica. 



The width of the anterior margin is a little less than one-third 

 the length of the body. There is no dorsal sinus; the frontal edge 

 of the dorsal plate is almost straight or very slightly concave. The 

 ventral sinus is U-shaped and somewhat angulate; its depth is two- 

 thirds the width of the anterior margin. Tlie stippled collar present 

 on both the dorsal and the ventral plate is unusually narrow. The 

 lateral edges of the lorica are slightly constricted immediately behind 

 the anterior margin, giving tliis a necklike appearance. 



The foot groove is shorter than in any other species of the genus, 

 its length being only one-fifth of the length of the lorica; the outline 

 is roughly trapezoid, truncate anteriorly, and with diverging sides. 

 The posterior width is nearly one-fourth the length of the lorica. 



The foot is approximxately one-fourth the length of the body; it 

 is fairly stout and its three joints are of nearly equal length. A 

 sensory pit on the terminal foot joint has not been observed. The 

 toes are extremely long, two-fifths the length of the lorica, and slightly 

 decurved; they taper rather rapidly to the nearly cylindrical or very 

 slightly conical posterior nortion. 



