314 ME. F. DAY ON THE RELATIONSHIP OE THE 



althougli it has representatives residing inland of species of 

 the genera Gohius, Sicydium, PeriopJithalmus, and Eleotris. 



" Mastacembeltdje (or Ehtnchobdellid^), 3 species in 

 Africa; 10 species " in the Indian region. — In the ' Catalogue' 

 vol. iii., Rhynchobdella 1 species, and Mastacembelus 8 species, 

 are given. In the ' Zoological Record ' are added in this region 

 Rhynchohdella sinensis, Bleeker, Mastacembelus fasciatus, 

 Bleeker, and M. Guentheri, Day. 



Chromides. — Two species of Etroplus are admitted from 

 India, E. canarensis, Day, being probably rejected : a figure of 

 this form from the life along with E. maculatus are therefore 

 exhibited, all three forms being fully described and figured in 

 the ' rishes of India ' and alluded to in the ' Zoological Record.' 



MuGiEiDJ^, omitted from the list of freshwater fishes in the 

 Indian region. One of the three forms, M. Hamiltonii, I dis- 

 covered in the fresh waters of Burma. Of Jf. corsula, Hamilton 

 Buchanan observes that it "is found in most rivers of the 

 Grangetic provinces, and in the southern parts of Bengal has 

 been introduced into some ponds " (Gangetic Eishes, p. 221) ; 

 of M. cascasia he remarks, " This fish I found in the northern 

 rivers of Bengal" (I. c. p. 217). According to my views these 

 Mullets, which live and breed in fresh waters, belong to the 

 freshwater fauna. 



" Ophiooephalid^ 30 species (1 fiom Africa)." — In the 

 Catalogue, 25 species of OpMocephalus and 1 of CTiauna are 

 stated to exist in the Indian region as defined in the ' Intro- 

 duction.' In the 'Zoological E-ecord' are 4 more species of 

 OpMocepJialus, with localities given, which would complete the 

 list. Although only one species, (I suppose) O. obscurus, Griinther, 

 is given from Africa, possibly O. africanus, Steind., from West 

 Africa, was unintentionally omitted. 



In questions of geographical distribution more information is 

 desirable than such as the following : " Ophiocephalidse are found 

 in India, China, and Africa; " for this might raise the supposition 

 that they were equally common in all these localities: such, 

 however, is by no means the case, they may abound in one or two 

 of those districts, but be very sparsely distributed in a third. The 

 abundance of forms ought to be considered along with their 

 presence. Again, if one genus of a family has representatives in 

 Africa, and 10 or 15 in Asia, it may be true that such a family is 

 common to both continents, but such is the case to only a limited 



