192. TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 
species. Common both as a free swimmer and in material 
dredged from a sandy bottom. It is easily recognised by 
its beautiful plumed anterior antenne and by the length 
of the inner branch of the second swimming feet. 
Lictinosoma spinipes, Brady. (Pl. XVIII, fig. 8.) 
Length 1.25 mm. Frequent in dredged material from 
a muddy bottom about low water mark. 
Hictinosoma curticorne, Boeck. Pl. XVIII, fig. 8. e.) 
Length 1.25 mm. This species is so nearly allied to 
the foregoing that I feel very doubtful as to its separate 
identity. The only important difference appears to be in 
the fifth feet and even here the gradation from one to the 
other is very slight. 
Ectinosoma erythrops, Brady. (Pl. XVIII, fig. 8. c. d.) 
Length 0.75 mm. Occasionally dredged in 10 fathoms 
off Puffin Island, and in 4 fathoms in Port Erin Bay. Its 
two brilliant red eye spots and the small size of the fifth 
feet are its distinguishing features. 
Lictinosoma melaniceps, Brady. (Pl. XXI, fig. 2. a.) 
Length 0.75 mm. Very similar in character to the 
three former species. Brady says ‘‘it is much smaller 
and more delicate in structure than H. spuwpes, and is 
moreover always distinguished by a cloudy blackish patch 
on the head.” We have taken it in the dredge at Port 
St. Mary and off the Calf of Man. 
Ectinosoma atlanticum, Brady & Rob. (Pl. XIX, fig. 1.) 
Length 0.50 mm. An easily distinguished species of 
slender build, long and narrow. ‘Taken by townet in the 
open sea occasionally, and on one occasion by electric 
light in Port Erin Bay. 
Tachidius brevicornis, Muller. (Pl. XXI, fig. 2. 6. c.) 
Length 0.80 mm. A brackish water species. We have 
taken it in quantity from material sent by Mr. Dwerry- 
house from a brackish tributary of the Mersey at Hale, 
