176 Mr. C. C. Babington's Observations 



tion, and have been repaid by the discovery of five marked forms 

 included under that name. The total ignorance which at present 

 exists on the subject of the limits of species in entomology, pre- 

 vents me from_giving any positive opinion upon the value of the 

 characters described in this communication, and I now submit them 

 to the Entomological Society under the idea that it is better to di- 

 stinguish marked forms by a specific name than to run the risk of al- 

 lowing good species to continue in obscurity by noticing them only 

 as varieties. I may add that the character given under all the 

 synonyms which I have been enabled to quote will apply to either 

 of the five species if colour is excepted. 



From an examination of the Linnsean cabinet it appears that the 

 insect described by Linnaeus in his later works under the name of 

 Dytiscus ferrugineus, and placed in his collection with that name 

 appended, in his own hand- writing, is not the Haliplus ferrugineus 

 of authors, but the same as D. ovalis, Linn. {Hyphidrus ovatus, Auct.) 

 described in his ' Faun. Suecica'. It would therefore appear that he 

 has introduced the same insect under both of these names in his 

 * Systema Naturae', ed. 1 767. The fact that Fabricius, who had free 

 access to the Linnsean collections, has no such insect as D. ferrugineus 

 in either of his works, would appear to prove that he was certain of 

 its nonexistence as a distinct species. Gyllenhal is the first au- 

 thor who has described anything under the Linneean name, and I 

 cannot suppose that he has had better, if such good, opportunities of 

 determining the question as we have in England. I have therefore 

 in the following description expunged the reference to Linnaeus, 

 and considered Gyllenhal as the first describer of H. ferrugineus. 



St. John's College, Cambridge, 

 April 8, 1835. 



Haliplus, Latr. 

 1. H. FEERUGiNEtTs, Gyll. Plate XV. fig. 2. 



Rufo-testaceus, nitidus, elytris profunde punctato-striatis inter- 

 stitiis seriebus punctorum minorum, thorace antice angusto, la- 

 teribus rectis, elytrorum, quorum maxima latitudo pone basin locatur, 

 lateribus rotundatis. (Long. corp. I4, lat. 4 lin.) 



H. ferrugineus, Gyll. Ins. Suec. i. 546. Steph. 111. (Mand.) ii. 40. 

 non Dytiscus ferrugineus, Linn. 



Reddish testaceous ; head broad, minutely punctured ; eyes slightly 

 prominent, black ; antennae pale, equal in length to the thorax, 

 which is much narrowed in front, emarginate, the anterior angles 

 acute, the sides straight, slightly margined, scarcely in continuity 

 with the elytra, posterior angles acute, distinctly punctured through- 



