1 84 



HARDWICKE'S SCIENCE-GOSSIP. 



Trichotropis borcalis, Cylichna alba, Mya truncata, 

 and other well-known European species. This is 

 exactly what we might expect, from the northern 

 character of the locality, but surely Southern 

 California would possess no European shells? On 

 the contrary, many of its genera are also European, 

 and Mr. C. R. Orcutt found Bulla vesicula (considered 

 perhaps a variety of hydatis), Pholas crispata, Saxicava 

 rugosa, and Lasea rubra in the vicinity of San Diego, 

 as well as Mytilus edulis, a species not only common 

 to Europe but to the Pacific coast of South America, 

 but which may possibly have been introduced from 

 its habit of clinging to the bottoms of vessels. 

 Also, a little Erachiopod, found at San Diego and 

 Todos Santos Bay, was referred by W. H. Dall to 

 Platidia anomioidcs, a species found in the Mediter- 

 ranean, North Atlantic, and Caribbean sea, though 

 whether this indicates a boreal origin, or an ancient 

 disconnection of North and South America, I 

 cannot say ; the latter theory is favoured by Dr. 

 Gunther's statement, that about 30 per cent, of the 

 fishes are identical on both sides of the Isthmus of 

 Panama. 



The marine alga; of California, like the mollusca, 

 include some European forms, and a list of those 

 collected by Mr. D. Cleveland at San Diego 

 enumerates such familiar species as Enteromorpha 

 compressa, Corallina officinalis, Fitcus vesiculosus, 

 Plocamium coccineum, Ulva lalissima, — all of which 

 I have myself collected at Margate on the Kentish 

 coast. 



Much that is interesting may be elucidated from a 

 study of the distribution of species on various parts of 

 the British coast. Many mollusca that are common 

 in Cornwall and the Channel Islands do not range 

 to the other end of the English Channel, and are 

 unknown in Kent : such are Trochus lineatus, which 

 takes the place of Littorina littorea, in the western 

 part of the Channel, T. magus, which extends as far 

 east as Hastings, and many others. Species thus 

 ranging over the western portion of the Channel 

 extend further east on the French than on the 

 English coast, a noteworthy instance of this being 

 Donax trunculus, which, though south-western and 

 very rare in England, is found on the north-east coast 

 of France and in Belgium. 



In comparing the lists of the marine shells of Kent, 

 Scilly Isles, and Yorkshire and Durham, I was 

 struck by the fact, that a number of species common 

 to Scilly Isles and Yorkshire and Durham are 

 unknown in Kent. How this most unexpected 

 circumstance is to be accounted for, I do not know, 

 and I very much regret that the almost total lack of 

 records for Lincolnshire, Norfolk, Suffolk and Essex 

 renders it impossible at present to trace how far these 

 species descend on the eastern coast. It is much to 

 be desired that conchologists having knowledge of the 

 occurrence of such species as Pecten tigrinus, Phiitne 

 scabra, Scalaria turtoncr, S. trcvclyana, &c, on the 



coasts of any of these counties will place the fact on 

 record, and any records whatever from the eastern 

 coast between Yorkshire and Kent would be of 

 exceptional value. 



In the present paper I have only been able to 

 indicate lines of enquiry, which may be followed out, 

 as circumstances allow, in the future. To do this, it 

 ii necessary to examine as many local lists as possible, 

 and I shall be very greatly indebted for the loan of 

 any such, and will do whatever may be in my power 

 in return for such assistance. I venture to hope that 

 others, having better opportunities than I, will give 

 some attention to the distribution of species round the 

 British coasts, so that there may be a better under- 

 standing of the true relations of the various local 

 faunae. 



West Cliff, Custer Co., Colorado. 



LIST OF BRITISH TABANIDiE, WITH 

 NOTES. 



By E. Brunetti. 



THE British species of Tabanidoe, though few in 

 number, seem to be very little understood by 

 students of Diptera, owing probably to the species 

 being very closely allied, their great variation, and 

 the extraordinary confusion existing in the synonymy. 



Professor Brauer's elaborate monograph on this 

 family (1880) has completely cleared up the confusion, 

 and I now venture to give a list of our British species, 

 adding such notes as may appear of interest. 



My best thanks are hereby tendered to Mr. Verrall 

 and Dr. Mason for very kindly placing their col- 

 lections at my disposal, and also to Mr. C. Dale and 

 Dr. Meade for much information on this group. The 

 collection of the Entomological Club (through the 

 kindness of Mr. B. Lowne), and the British Museum 

 collection, have also been carefully examined, nearly 

 a thousand specimens having passed through my 

 hands. 



Schiner, in 1868, admitted 1122 species in this 

 family, 106 or thereabouts being European. Nine 

 genera are European, five being represented in 

 Britain. 



I. Tabanus, Linn. 1766. 



Linn. Sys. Nat. (1766). 



1. T. bovinus, Linn. 1766. — Linn. Sys. Nat. ii. 

 1000 ; tropicus, Harris ; larva, De G. Ins. vi. 6. 



This is usually considered the commonest species, 

 but it is much less common than the next species, 

 T. Sudcticus, which is very frequently mistaken for 

 bovinus. In Dr. Mason's collection I found a very 

 small <$ measuring only 18 mm. 



2. P. Sudcticus, Zell. 1842.— Zell. Isis (1842), 815, 

 pi. i. 5-8 ; bovinus, Mg. 



Professor Gobert thinks this a variety of T. spo- 



