BIHANG TILL K..SV. VET.-AKAD. HANDL. BAND 11. N:o 15. 15 
1874. Cecidotea stygia. PACKARD. S. I. SMITH. >The Crustacea 
of the fresh waters of 
the United States>. 
Rep. of the U. S. Com- 
missioner of the Fish 
and Fisheries. Part 2, 
p- 661. 
The head is as broad as long, twice as long as the first 
pereional segment, and of the same breadth. The second 
pair of antenne are a third longer than the body. The first 
pair of pereiopoda are shorter than the following. The pleon 
is longer than broad, as long as the last three pereional seg- 
ments together; with a very slight median projection behind. 
The uropoda are longer than the pleon; the outer ramus is 
very short, the inner four times longer, but only half as long 
as the peduncle. 
Colour. White, translucent. 
Length. 1—8 mm. ' 
Hab. The Mammuth Cave in Kentycky. Wells in Indi- 
ANG UK SCA. 
Gen. III. Leptapsidia. SPEscE BATE and WESTWOoOD. 
Syn. 1863. Leptapsidia. SPENCE BATE 
and WESTWOOD. A History of the British Sessile- 
eyed Crustacea. Vol. 2, p. 331. 
London. 
Diagn. Corpus latum, depressum. 
Caput maximum, semicirculare. 
Oculi nulli. 
Antenne primi paris longe, flagello IV-articulato instruct2e. 
Antenne secundi paris long, fagello V-articulato instruct2e. 
Latera segmentorum pereii valde producta, non laciniata, bases 
pedum tegentia. 
Pedes pereii primi paris subceheliformes, ceteri subequales. Dac- 
tyli pedunculati (?) uni-unguiculati. 
Pedes uri pedunculo perbrevi, ramis carente. 
The body is broad, very flat, pear-shaped. 
The head is very large, semicircular. 
Eyes are wanting. 
The first pair of antenne are long, with four-jointed fa- 
gellum. 
The second pair of antenne are long, with five-jointed 
fagellum. Both pairs are fixed on the underside of the head. 
