THE FAIRY SHRIMPS (PHYLLOPODA) 673 



60 (53) First and second post-cephalic limbs prehensile in the male; carapace 



distinctly bivalve, enclosing head, with concentric growth 

 lines around a more or less prominent umbo. 



Family LIMNADIIDAE . . 61 



6 1 (66) With pediculated dorsal organ on front of head 62 



62 (63) Shell broad oval, much flattened, subtriangular, with about 18 lines 



of growth; flagella of second antenna 12- to i3-segmented; 



1 8 to 22 pairs of limbs Limnadia. 



Only one species Limnadia americana Morse 1875. 



This species was described from specimens collected 

 at Lynn, Massachusetts. 



Another possible species, Limnadia coriacea Halde- 

 man, was collected at Cincinnati and in ditches along 

 the Susquehanna river, but it has not been sufficiently 

 described so that its relationships can be determined. 

 See Packard (1883, pp. 313, 314). 



FIG. 1041. Limnadia americana. Side view. X 3. 

 (After Packard.) 



63 (62) Shell narrow-ovate, rather prominent behind the umbones with 4 to 



5 lines of growth; flagella of second antennae 9- to zo-seg- 

 mented; 18 pairs of limbs Eulimnadia . . 64 



64 (65) Shell narrow-ovate, with 4 lines of growth; telson with 12 pairs of 

 1 J ^ dorsal spinules not including the terminal spine. 



Eulimnadia agassizii Packard 1874. 



This small crustacean has only been observed on 

 Penikese Island, Massachusetts. The figure shows 

 the large dorsal organ projecting above the eye. The 

 valves of the carapace are whitish and very trans- 

 parent. Their shape is regularly oval. 



FIG. 1042. Eulimnadia agassizii. Side view. X 4. 

 (After Packard.) 



65 (64) Shell narrower than that of Eulimnadia agassizii, with 5 lines of growth ; 



telson with 16 fine teeth above. 



Eulimnadia texana Packard 1877. 



The valves of the carapace are whitish and 

 rounded oval in shape. 



This species has been collected in Kansas, 

 Nebraska, and Texas. It is said to be com- 

 mon in the last locality in early spring. The 

 figure shows only the shape of the shell. 



FIG. 1043. Eulimnadia texana. Shape of shell, 

 side vkw. X 7. (After Packard.) 



66 (61) Shell oval, more or less globose, with 18 to 22 lines of growth, amber 



colored; no pediculated dorsal-organ on front of head; 

 flagella of second antennae n- to ly-segmented; 24 to 28 

 pairs of limbs Estheria . . 67 



