26 
Fam. 3. Platyaspidae. 
Characters. Body considerably dilated in front, with the carapace very 
large and applanated, pseudorostral projection distinct, antero-lateral corners obso¬ 
lete. All 5 pedigerous segments distinctly exposed, the 1st being of unusual 
size. Tail slender and narrow. Antennae and oral parts of a similar structure 
to that in the Lampropidce. Legs, however, very different, the 4 posterior pairs 
being quite simple in female, without any traces of exopodites; all pairs in male, 
except, the last, provided with well-developed natatory exopodites. 3 pairs of pleopoda 
present i male. Uropoda slender, resembling somewhat in structure those in the 
Lampropidce. Telson distinctly defined, conically tapered, terminating with 3 spines. 
Remarks.— 1 have felt justified in establishing this new family, to include 
the anomalous genus Platy asp is, formerly referred to the Lampropidce. It is true that 
in certain points this genus seems to approach that family, namely, as regards 
the structure of the antennas, oral parts and terminal caudal appendages, as also 
in the number of pleopoda in the male; but there are several other characters, 
in which it differs so very essentially, as scarcely to allow of its being included 
in the said family. The carapace, for instance, is of quite a peculiar structure, unlike 
that in any other known Cumacea, and the 1st pedigerous segment exhibits a 
development likewise unique in this order. Finally, the structure of the legs is 
very unlike that in the Lampropidce , and more resembles that in the Cumidce, at 
least as regards the female, in which only the 1st pair is provided with exopo¬ 
dites. Besides the typical genus Platyaspis, I am of opinion that the genus 
Chalarostylis of Norman ought to be referred to this family. The latter genus, 
however, is still but imperfectly known, having only been founded upon a solitary 
specimen of the male sex. 
Gen. Platyaspis, G. O. Sars, 18fi9. 
Generic Characters. —Carapace large and broad, slightly vaulted above, 
sides greatly expanded, fornicate; pseudorostral projection triangular. 1st pedi¬ 
gerous segment much larger than any of the others. Integuments rather thin, 
squamous. Eye wholly absent. Superior antennae with both flagella well deve¬ 
loped and nearly equal, the outer one in male provided at the base with numerous, 
