i62 ANNALS OF SCOTTISH NATURAL HISTORY 



the chitin lies along the median line and is pointed at both 

 ends. The entire edge is thickened so that the median eye 

 appears to lie in a space surrounded by a ridge. The 

 pigment body resembles a double star in shape. T, 

 longirostris has already been recorded for England and 

 Ireland. 



Tiphys liliaceiis^ Miiller. — This species was mentioned 

 by Miiller in his " Prodromus," and in his treatise in 1781 

 on the Danish Hydrachnids, he gave it the name oi Hydrachna 

 liliacea. The only other species of Tiphys on record for 

 Scotland are T. ligulifer^ Piersig, which constituted a new 

 British record, and T, cassidifonnis, Haller, both found near 

 Oban. 



In 1835, Koch, who is responsible for some complication 

 in Hydrachnid nomenclature, used the generic name Tiphys, 

 which he replaced in 1837 by Acercus. Haller in 188 1 

 changed the name to Forelia. Oudemans in 1897 reverted 

 to Tiphys. In the same year Piersig adopted the name 

 Acercus, which he discarded in 1900 for Tiphys. In 1906 

 Koenike adopted Haller's name of Forelia for the genus. 



Dr. Sig Thor in Norway, Dr. F. Koenike in Germany, 

 and Dr. R. H. Wolcott in Nebraska, U.S.A., have reviewed 

 the evidence for the correct name for this genus. Thor 

 holds that the names Tiphys and Acercus are properly re- 

 ferable to species other than those embraced in the genus 

 under consideration, and that consequently Haller's name 

 Forelia, with F. cassidiformis as type, must take precedence. 

 Koenike also upholds Forelia, but he has changed the specific 

 name from cassidiformis to parniata. Wolcott, on the other 

 hand, rejects the claims of Acercus and Forelia, and supports 

 the use of Tiphys, designating T. liliacens as the type species. 

 In this connection it is interesting to note the opposite 

 views in regard to Koch's work of two such authorities as 

 Sig Thor and R. H. Wolcott 



Sig Thor, in the "Nyt Magazin for Naturvidenskaberne " 

 for 1903, says, "Die Gattungen Acercus und Tiphys waren 

 schon friiher von Koch hinreichend charakterisirt." Wolcott 

 in " Studies from the Zool. Lab. of the University of 

 Nebraska," No. ()6 (also "Trans, of Amer. Micro. Soc," 

 xxvi. 214), says, "Koch in 1835 described and figured 



