204 Copepoda living as Parasites or Messmates. [Sess, 



described and figured in Part III. of the ' Twentieth Annual 

 Eeport of the Fishery Board for Scotland,' p. 455, pi. xxv., 

 figs. 8-15. Nereicola ovata is a species which Professor 

 M'Intosh of St Andrews obtained on the shores of the Channel 

 Islands adhering to specimens of Nereis cultrifera Grube. The 

 Professor very kindly sent me his specimens of Nereicola that 

 I might myself compare them with those from the Uulalia, 

 and also indicated where he thought the two forms differed. 

 The fragment of Eulalia with the Nereicola adhering to it was 

 obtained in a gathering of dredged material from Loch Etive, 

 Argyleshire. 



In the ' Annals and Magazine of ISTatural History ' for 

 March 1898 a curious copepod was described in a paper by 

 my son and myself under the name of Eitrynotus insolens. 

 Eitrynotics, which means broad-shouldered, was given to this 

 copepod because the cephalo-thoracic segment was somewhat 

 larger than usual. The specimens were not attached to any 

 host, but an examination of the mouth-appendages led us to 

 remark that " the species appeared to be either a parasite or a 

 commensal." We were therefore not greatly surprised when 

 a considerable time afterwards Dr Steuer, Trieste, informed us 

 that he thought the species we had described was probably 

 identical with JEttnicicola Claiisi Kurz, a parasite on Eunice sp., 

 — an opinion we also now share. This copepod seems to be 

 rare. It has been observed on one or two occasions in the 

 Clyde, but has not yet been noticed on the east coast. 



Before passing on to consider some of the copepods asso- 

 ciated with other crustaceans, there is another example of a 

 copepod and an Annelid living together that I shall briefly 

 refer to because of their habitat. This copepod is called 

 Hersiliodes latericius (Grube), and its host is known as 

 Leioclione clypeata. Two species of Hcrsiliodcs are found in 

 the Forth, H. littoralis (T. Scott) and H. aberdonensis, but H. 

 latericiics, which has not yet been observed in Scotland, has, 

 together with its host, been discovered by Mr Arnold T. 

 Watson at Hunstanton, on the coast of Norfolk. The same 

 copepod (or one very closely allied to it), with what appears to 

 be the same worm as host, are found together at Cherbourg, in 

 France, and at both places there is a submarine forest. Mr 

 Watson, in his remarks on the species, states that the 



