1904-1905-] Copepoda living as Parasites or Messmates. 207 



new species, my son and I published a description of it under 

 the name of Lichomolgus agilis, but we afterwards learned that 

 it had been described by Dr Canu of Wimereaux, Boulogne- 

 sur-Mer, the year previous, so we were again too late. Dr 

 Canu has obtained Herrmannella rostrata in Mactra shdtoruin 

 and Pecten opercidaris, as well as in the cockle. 



Another species which Dr Canu records from Pecten oper- 

 cularis is Modiolicola inermis, but this I have not seen. I 

 have at various times, however, found specimens of another 

 very pretty Modiolicola — viz., M. insignis Aurivelius. This 

 species is not uncommon in the large horse-mussel {Mytilus 

 modiolus, or Modiola modiolus as it is sometimes called). The 

 distribution of the copepod seems to be coextensive with that 

 of the mollusc. 



A small but very neat species — LicJiomolgios agilis Leydig 

 — not the species my son and I described under that name — 

 lives on the branchial plumes of Poris tubei'ctdatus, and has 

 been found in the Firths of Forth and Clyde. Another fine 

 species, Artotrogus orbicularis Boeck, which I have taken in 

 the Clyde, and which the late Mr I. C. Thompson also obtained 

 in the Irish Sea, though not found by either of us attached to 

 any host, is reported as living on a species of Poris. Boeck 

 is said to have found the species on a Poris at Farsund, in the 

 south of Norway. Another curious species, Anthessius solecurti, 

 is found on the common " spoot-fish " (Solen siliqua). Several 

 other species might be mentioned ; but enough has been said 

 to show that there may still be work to do even in such a 

 limited field of Natural History study as that I have now been 

 dealing with. In any case, the day is yet far distant when 

 the student of Natural History will have to sit down and 

 mourn, like Alexander, because he has no more worlds to 

 conquer. 



At this meeting Mr E. A. Staig read a paper entitled 

 " Nature-Study and the Citizen." 



VOL. V. 



