354 Mr. W. Thompsou^s Additions to the Fauna of Ireland. 



with any described species. They were submitted to Pi'ofessor Bell 

 for the use of his work on the British Crustacea, and proved to be 

 of a species that he considered new, and of which he had just drawn 

 up a description under the name of //. imndaliformis. " This name " 

 (he observed) " suggested itself from their leading to the typical 

 Palsemons through Pandalus ;" a peculiarity of structure which had 

 also attracted my attention. 



2. Idotea acuminatum, Leacli ? 



Among Crustacea kindly sent from Dublin for my inspection by 

 R. Ball, Esq. were two individuals of an Idotea 10 lines in length, 

 very distinct in form from our three common species, the /. pelagica, 

 I. entomon and /. oestrum of Leach. They were purchased of Mr. 

 M'Calla, but on what part of the coast taken was not stated. I mark 

 the species with doubt on account of Leach's only specimen in the 

 British Museum, with which they were compared, being in a bad 

 state of preservation. The /. acuminatum was first noticed in the 

 British Museum catalogue of Crustacea, p. 95 (published in 1847), 

 as among Dr. Leach's inedited species. He obtained it on the coast 

 of Devon, and called it in his MS., Leptosoma lancifer. 



3. Caligus Nordmanni, Edvv. Hist. Crust, vol. iii. p. 455 ; and 



Atlas, Cuv. Reg. Anim, pi. 77. f. 1. 



I took several specimens of this fine Caligus alive on a sun-fish 

 {Orthagoriscus mola) captured on the coast of Antrim in September 

 1848. They were all adherent externally to the skin of the fish on 

 diflferent parts of the body. When living they were marbled over 

 with grayish lilac of dark and light shades. This species was erro- 

 neously included in a paper published in the 20th vol. of the ' An- 

 nals,' p. 248. The name C. Mulleri being substituted there for C. 

 Nordmanni will make all correct. Two others noticed in the same 

 page require the following correction, according to Dr. Baird, who 

 then kindly assisted in determining them, but has since given the 

 subject a more rigid examination. 



Caligus vespa should be Cat. Stromii, a species since described by 

 Dr. Baird in the Report of the Berwickshire Naturalists' Club for 

 1847, p. 259*. 



Caligus sturionis should be Cat. rapax, Edw. Hist. Crust, vol. iii. 

 p. 453. pi. 38. f. 9. 



Ann*elida. 



1. Planaria flexilis, Dalyell, Observ. on Planariae, p. 5. f. 1, 2. 



April 14, 1848. I found at Cultra, Belfast bay, two Planaria of 

 this species adherent to the under side of a stone between tide-marks, 

 and brought them home in sea- water to be observed at leisure. When 

 fully extended they are 6 lines long, and at the head 2^ broad, be- 

 coming thence gradually narrower. Eyes commencing at the distance 

 of a line from the anterior extremity of the body ; all extremely mi- 

 nute, but differing in size ; disposed irregularly in a somewhat cres- 

 centic form on either side a transparent circle. The vessels along 



* [See also Annals, vol. i. Ser. 2. p. 396.] 



