EYES OF A RUBY RED 275 



almost quadrate, deeply incised. This, the single repre- 

 sentative of the genus, was obtained from 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 antennae 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 small 

 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 Dana's 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. 



Erythrops, ' the red-eyed,' was a name given by Sars in 

 1869 to part of the genus Nematopus, a preoccupied name 

 which he had used in 1863. 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. Erythrops serratn.$, 

 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.' Erythrops erythro- 

 plitlialmus (Goes) refers to this colouring of the eyes both in 

 the specific and generic names. Sars changed the name of 

 Goes' species, which had been originally assigned to Mysis, 

 into Nematopus Goesii, 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. Ei'i/tJirops pygmceus, Sars, has been identified by 

 Sars with his own earlier Nematopus elegans, so that the 

 name must be Erythrops elegans. Pa/rerythrops obesus, Sars, 

 was at first doubtfully included in the genus Nematopus^ 

 with the other more slender species. 



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