On Mr. Swainson's genus Thelidomus. 257 



1834. By Dr. Bellingham of Dublin I have been favoured 

 with specimens, which he found attached to the gills of whiting 

 (^Merlangus vulgaris) brought to the market of the metropolis. 

 ^Lerncea cornuta. Mull. Z. D. vol. i. p. 40. tab. 33. f. 6. 

 Ehtomoda cornuta, Lam. t. 3. p. 686, 2nd ed. To Dr. Bellingham 

 I am indebted for specimens of this Entomoda, which were 

 found by him attached to the gills of sole, purchased in Dublin 

 market in May 1837. 

 Chondracanthus Lophii, Johnst. Mag. Nat. Hist. vol. ix. p. 81. f. 16. 

 The first specimens which I have seen were procured by Dr. 

 Scouler on a Lophius piscatorius in Dublin — more recently they 

 occurred to myself, in the pouches of a fish of the same species 

 brought to that city. 

 In concluding the present " Additions," it may be mentioned, 

 that as a further step towards a Fauna of Ireland, I intend publish- 

 ing catalogues of the species contained in all the departments which 

 have occupied my attention, whenever they may have been satis- 

 factorily investigated, giving at the same time such details as may 

 seem desirable. 



XXIX.— On the " Freshwater Carriers," or Thelidomus of 

 Mr. Swainson. 



Mr. Swainson in his Malacology, a recent volume on 

 " Shells and Shell-fish," has estabhshed a genus, under the 

 name Thelidomus, upon two bodies which he received with 

 some Planoj'besf from Brazil. These *^two Helix-looking 

 shells," as he calls them, he considers as " absolute counter- 

 parts of" the carrier Trochi, and states that they " fill the 

 same situation among the Rofellina which Onustus (the carrier 

 Trochus) does among Trochin(B" He also represents them as 

 forming a passage from these animals to the Helices, and ob- 

 serves that the "^ discovery of this extraordinary shell will 

 probably induce naturalists to a more accurate examination 

 of the fossil turbinated univalves than they have received ; 



* Lerncsa branchialis, Linn, Guerin Icon. Regne. An. Zoop. pi. 9. f. 1. 

 gadina;, Mull. Z. D. vol. ill. p. 65. tab. 118. 



This species is published as Irish by Mr. J. V, Thompson. By Mr. 

 Glennon, of Suffolk Street, Dublin, 1 have been presented with specimens, 

 of which he procured several from the gills of a cod brought to the market 

 of that city. 



f Mr. Swainson's plural is Planorbi. — Ed. 



Ann. Nat. Hist. Vol. 5. No. 31. June 1840. t 



