PACKARD. ] PHYLLOPODS OF NORTH AMERICA. 311 
Genus LIMNADIA Brongniart. 
Limnadia Brongniart, Mémoires du Muséum d’Hist. Nat. VI, Pl. 13, 1820. 
Milne-Edwards, Hist. Nat. des Crustacés III, 561, 1840. 
Shell broad, flat, with about 18 lines 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 2o22- breadth. O27. 
Museum of Peabody Academy, collected by Mr. Tufts, at Lynn, Mass. 
Genus EULIMNADIA Packard. 
Eulimnadia Packard, Sixth Report Peab. Acad. Se. Salem., 55, June, 1874. 
Hayden’s U. 8. Geol. and Gevgr. Surv. Rep. for 1873; 618, 1874. 
Shell Lee, oblong, oval, not nearly as wide as in Limnadia, with 
only 4 or 5 lines of erowth: the dorsal edge straighter, less curv ed than 
in Limnadia; 18 pairs of feet. The head and antenne do not differ 
essentially, but the gills are much larger than in Limnadia; while the 
upper or dorsal lobe of the flabellum is much smaller than in Limnadia. 
The Australian Limnadia stanleyana King and L. antillarum Baird are 
congeneric with our H. agassizti and texana. 
Synopsis of the Species. 
Shell narrow-ovate, with 4 lines of growth .....-.-- Weciees HH. agassizii. 
Shell narrower than in preceding, more oblong, with 5 lines of growth; 
2d antenne longer, more spiney and hairy than in foregoing spe- 
PAC SU eat ee Fa caalbiacd i acts ee a tee: IS Bt E Le Re lira hea E. texana. 
EULIMNADIA AGASSIzIt Packard. 
Plate VII, figs. 5, 6. 
Eulinnadia agassizii Packard, Sixth Rep. Peab. Acad. Sc., 54, 1874. 
Hayden’s U. 8. 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 EH. texana. First 
antennz much shorter, smaller and 
less distinctly segmented than in 
LH. tevana, not reaching beyond the 
middle of the stem or scape of the 
2d antenn, while in H. texana they 
reach to the basal joint of the fla- 
: : se Fic. 14.—Hulimnadia agassizii Packard, en- 
gella. Secondantenne with 9 joints larged about 6 times. 
to each flagellum. In the upper flagellum but a single seta at the end 
of each joint, while there are four or five in HL. texana ; the set on the 
