60 BRITISH COPEPODA. 



distinction. With this view I have here discarded the 

 name Ascomyzon, which, though pubhshed in the same 

 year with Artotrogus, seems to have been a httle later, 

 M. Boeck's pamphlet being referred to in M. Thorell's 

 work on the * Crustacea inhabiting the Interior of 

 Ascidians.' Asterocheres is set aside as being generi- 

 cally synonymous with the less objectionable term 

 Artotrogus. 



1. Artotrogus Boeokii, Bradij. PL XCI, figs. 1 — 9. 



Ascomyzon Lilljeborgii, Thorell, Om Krustaceer i Ascidier, p. 78, 

 tab. xiv, fig. 21 (1859). 



Anterior antennae 20-jointed, exactly similar in struc- 

 ture to those of the preceding genus. Mandibles 

 simple, produced into a long filiform seta, and desti- 

 tute of a palp '(PI. XCI, fig. 3). Fifth pair of feet 

 cihated on the margins, and bearing two apical setae. 

 First abdominal segment fringed below the middle on 

 each margin with a series of about ten short setae. 

 Caudal segments about as long as broad ; setse five, 

 the larger ones about as long as the abdomen and 

 finely plumose. 



I know this species only from two or three speci- 

 mens taken in the surface-net, and amongst weeds, at 

 a depth of two fathoms, in Westport and Roundstone 

 Bays, Ireland. M. Thorell's specimens were obtained 

 from Ascidia jparallelogramma, in which he states that 

 it frequently occurs. I have not myself seen any 

 examples taken from Ascidians. 



