PACKARD ON NEW PHYLLOPOD CRUSTACEA. 



175 



frontal, interantennal, shrub-like, branched, biramous appendage ex- 

 tending out in front, the brush more than half the length of the body, 

 and sending off branches anteriorly. 



Female. The frontal shrub is entirely wanting, while the second an- 

 tennse are remarkably long and broad, oar-like, acute at the tip. The 

 egg-sac is long, subcorneal, rather thick and broad at the base, which 

 is concealed by the leaf-like feet ; it ends in two valves. 



In both sexes, the body is unusally short and thick, though the head 

 is of the usual size. Feet with the lobes broad and short, much more 

 orbicular than usual ; the abdomen dilates into a remarkably large, 

 broad, lin-like expansion, beginning at the sixth segment from the end, 

 and expanding at the last segment until it becomes wider than the 

 body, and extending a little way beyond the last segment. It is fringed, 

 and canals from the body ramify in it; at the end deeply notched, form- 

 ing two broad, rounded lobes. 



This remarkable genus differs from any other known to me by the 

 short and broad, spatulate, fin-like expansion of the abdomen, while 

 the male claspers are curved and simple. In both sexes, the body is 

 stout, broad, and the egg-sac of the female is subconical, spreading 

 out at the base. It is quite unlike any European genus. 



ThmmioeepJialus platyurus, n. sp. (Figs. 14, 15, male; 14, a, head of female ; 

 14, &, ovisac). — Male. — Frontal shrub over half as long as the body, the two 

 branches subdividing into about seven sub-branches, all directed forward . 

 First antennse long and slender, extending to the end of the basal joint 

 of the second or male claspers. The latter with the 

 basal joint rather short, the claspers long, slender, 

 and recurved, simple, saber-like, chitinous, the lower 

 lobe soft, acute, subconical. Genital appendages in 

 the usual position, short, not 

 so long as the segment to 

 which they are attached, and 

 bilobed, there being two 

 short terminal tubes, with 

 distinct, large openings, di- 

 rected downward. 



Female. — Second antenncne 

 large and long, extending 

 back a little beyond the base 

 of the ovisac, oar-like, ex- 

 panding broadly on the outer 

 two-thirds, especialy on the 

 upper edge. The ovisac is 

 subconical, the base broad and concealed by the limbs; it terminates 

 at the posterior edge of the fourth segment from the end, ending in two 

 unequal iiaps, the upper four times larger than the under flap, and trian- 

 gular in outline. 



^rt--> 



Fig. 



¥10. 14.— Thamnoce2)halus platij- 

 iirus, Pack., n. sp., male, natural 

 i^ize. ti. i;, head and end of body of hts platyurus, 

 female, showing ovisac. ural size. 



15. — Thamnoceplia- 

 male, uat- 



