6 C. BOVALLIUS. REMARKS ON THE GENUS CYSTEOSOMA. 
1. Thaumatops Neptunus. GUÉRIN-MÉNEVILLE. 
Syn. 1842. Cystisoma Neptunus. GUÉERIN-MÉNEVILLE, 1. c., p. 215, pl. 
1,8 
1832. 2 > 2 J.J. DANA, leg 
p. 981. 
1862. Cystosoma Neptuni. 2 SPENCE-BATE, 1. 
& pra, plc 
30, BE dT 
1874. Thaumops pellucida. R.V. WILLEMOÉS-SUHM. Phil. Trans, Roy. 
Soc. Lond, vol. 
163, part. 3, p- 
637. (the male). 
1875. Cystisoma Neptunus. GUÉRIN-MÉNEVILLE. R.V. WILLEMOÉS- 
SvM. = Trans. 
Linn. Soc. Ser. 
2. vol. 1, part 1, 
p. 24, pl. 2, fig. 
4—38. 
Diagn. Caput segmentis quinque primis pereii longius, longitudine altitudi- 
nem &equans. 
Segmentum primum et secundum pereii coalita. 
Antenne primi paris capite breviores, recte. 
Metacarpi pedum pereii parium duorum priorum processu carpi lon- 
giores. Pedes pereii quinti paris illis septimi paris duplo lon- 
giores, 
Segmentum ultimum uwri carinatum. 
Pedunculi pedum wuri ultimi paris ter fere longiores ramo externo. 
Ramus externus, internum longitudine zxquans. 
The head is longer than the five first pereional segments, 
as long as deep. 
The first and second pereional segments are coalesced. 
The first pair of antenne are shorter than the head, 
straight. 
The metacarpi of the two first pairs of pereiopoda are lon- 
ger than the corresponding carpal processes. 
The fifth pair of pereiopoda are twice as long the seventh 
pair. 
The last ural segment is keeled on its dorsal side. 
The peduncles of the last pair of uropoda are almost 
three times longer than the outer ramus. The outer rtamusis 
as long as the inner coalesced one. 
The head is broader and deeper than the pereion, tumid, 
globular. From the base of the antenn&e there runs on each 
