PACKAED.] 



PHYLLOPODS OF NORTH AMEEICA. 



311 



Genus LIMKADIA Brongniart. 



lAmnadia Brongniart, M^moires <lu Museum d'Hist. Nat. VI, PI. 13, 1820. 

 Milne-Edwards, Hist. Nat. des Crustaces III, 561, 1840. 



Sliell broad, flat, with about 18 Hues of growth, disappearing near the 

 very flat nearly obsolete beaks; 22 pairs of feet. 



LiMNADIA AMERICANA Morse. 



Limnadia americana Morse, Proc. Bost. Soc. Nat. Hist. XI. First Book of Zoology. 

 Fig. 138, L., 1875. 



Shell (Fig. 13 in text) large, broad, ovate, much flattened, with 18 lines 

 of growth; smooth and shining; allied to L. gigas of Europe. 

 Length of shell, 12.5™"; breadth, 9"™. 

 Museum of Peabodj' Academy, collected by Mr. Tufts, at Lynn, Mass. 



Genus EULIMISTADIA Packard. 



Eulimnadia Packard, Sixth Report Peab. Acad. Sc. Salem., 55, June, 1874. 

 Hayden's U. S. Geol. and Geogr. Surv. EejD. for 1873 ; 618, 1874. 



Shell narrow, oblong, oval, not nearly as wide as in Limnadia^ with 

 only 4 or 5 lines of growth ; the dorsal edge straighter, less curved than 

 in Limnadia ', 18 pairs of feet. The head and antennae do not differ 

 essentially, but the gills are much larger than in Limnadia: while the 

 upper or dorsal lobe of the flabellnm is much smaller than in Limnadia. 



The Australian Limnadia stanleyana King and L. antillarum Baird are 

 congeneric with our L. agassizii and texana. 



Syno])sis of the Species. 



Shell narrow-ovate, with 4 lines of growth LJ. agassizii. 



Shell narrower than in preceding, more oblong, with 5 lines of growth; 

 2d antennae longer, more spiney and hairy than in foregoing spe- 

 cies U. texana. 



Eulimnadia agassizii Packard. 



Plate VII, figs. 5, 6. 



Eulimnadia agassizii Packard, Sistli Rep. Peab. Acad. Sc, 54, 1874. 



Hayden's U. S. Geol. and Geogr. Surv. for 1873. 618, 1874. 



Carapace valves whitish, very transparent, quite regularly oval, nar- 

 rower than usual, somewhat trun- 



cate at the end, widest slightly in 

 front of the middle, with four lines 

 of growth, valves much more con 

 vex than in Limnadia americana. 



Head with the "haft-organ" 

 larger than in E. texana. First 

 antennae much shorter, smaller and 

 less distinctly segmented than in 

 E. texana^ not reaching beyond the 

 middle of the stem or scape of the 

 2d antennae, while in E. texana they 

 reach to the basal joint of the fla- 

 gella. Second antennae with 9 j oints 

 to each flagellnm. In the upper flagellum but a single seta at the end 

 of each joint, while there are four or five in E. texana ; the setae on the 



Fig. 14. — Eulimnadia 

 lareed about 6 times. 



agassizii Packard, 



