EYES OF A RUBY RED 275 
almost quadrate, deeply incised. This, the single repre- 
sentative of the genus, was obtained trom depths beyond 
eleven and twelve hundred fathoms in the Northern Ocean. 
Anchialus typicus, Kroyer, belongs to a genus in which 
the scale of the second antennz is remarkably small, the 
pleopods in the male well developed, but partly obsolete in 
the female. ‘The telson is large and incised at the apex. 
The female has on the first segment of the pleon smail 
horizontally projecting side-plates. Of the small but ro- 
bust and very broad species Anchialus agilis, Sars, a speci- 
men is recorded from Plymouth. Anchialus pusillus, Sars, 
from the Pacific, was at first assigned to Danas genus 
Promysis. The specimens described have greatly developed 
marsupial pouches, from which it is inferred that they were 
full-grown, and yet in length they barely attain one-eighth 
of an inch, about as small a size as an adult shrimp could 
well be expected to content itself with. 
Hrythrops, ‘the red-eyed,’ was a name given by Sars in 
1869 to part of the genus Nematipus, a preoccupied name 
which he had used in 1865. As the earlier name implies, 
the legs are very slender, nearly filiform. ‘They terminate 
in a well-formed nail. ‘The telson is very short, scarcely 
longer than broad, apically broadly truncate. Of the three 
species here mentioned, all are British. Hrythrops serratus, 
Sars, is distinguished by Norman ‘from all other British 
Mysidea by the serrations of the outer margin of the an- 
tennal scale.’ He says that ‘ the very large - reniform eyes 
are of a lovely and brilliant ruby red. E’rythrops erythro- 
phthalmus (Goés) refers to this colouring of the eyes both in 
the specific and generic names. Sars changed the name of 
Goés’ species, which had been originally assigned to Mysis, 
into Nematopus Goésii, on the very ground that the red- 
ness of the eyes was common to all the species of the new 
genus, but the earlier name should be retained notwith- 
standing. Hrythrops pygmceus, Sars, has been identified by 
Sars with his own earlier Nematopus eleyans, so that the 
name must be Hrythrops elegans. Purei -ythr ops obesus, Sars, 
was at first doubtfully included in the genus Nematopus, 
with the other more slender species. 
