243 



and Loretoyacu, on the Peruvian Amazons. The collection contained exam- 

 ples of new species of Thamnophilus and of Crypturus , which were proposed 

 to be called T. loretoyacuensis and C. Balstoni. — A communication was read 

 from Mr. Edgar A. Smith containing an account of the collections of ter- 

 restrial and fluviatile Mollusca lately made in Madagascar by Mr. W. John- 

 son and the Rev. W. Deans Cowan. Various new and interesting species of 

 the genera Cyclostoma, Vitrina, Helix, Stenogyra, Melanatria, Cleopatra, Am- 

 pidlaria, Limnaea, Physa, Planorhis, Corhictda, and Pisidium were described. — 

 P.L.Sclater, Secretary. 



2. Linnean Society of London. 



March 16, 1882. — Mr. Smith showed a bee caught alive in this 

 country, and having a profuse growth of the Isaria condition of the Cordi- 

 ceps sphecocephala, a W. Indian form, the letter genus being closely allied 

 to Claviceps, or Ergot. — Dr. Francis Day read a paper upon the Salmones 

 found in the British Isles, remarking how great changes are occasioned by 

 retaining any of them in unsuitable localities. He objected to the augmen- 

 tation in number of the British forms of non-migratory Trout from three to 

 seven, as made by Dr. Günther, holding that we possess only two : — the 

 Loch Leven Trout, which is in reality a marine form acclimatized to fresh 

 water, whereas the remainder are solely local races of the common Brook 

 Trout. A most interesting fact was brought forward, viz. that Mr. Arthur, 

 in New Zealand, having lately examined the Trout which were introduced 

 in 1869, from ova originally obtained from the Thames and the West of 

 England, found great structural changes had taken place. The fish in que- 

 stion, moreover, living in difi"erent streams in New Zealand, had also assu- 

 med local peculiarities of size and change of form ; and, due doubtless to 

 increased food, the annual increment of weight had risen from 1 Y2 to 2^/2 

 pounds, and an example had been seen weighing 20 pounds. The coecal 

 appendages, hitherto held as significant of species, were found augmented from 

 33 to 50, as exemplified in British fish, to from 43 to 54 in the New Zealand 

 examples, showing that these organs are inconstant in number. Having allu- 

 ded to the different species, Dr. Day concluded that, as the various species 

 of non-migratory Trout, accepted by Dr. Günther, interbreed, and the hybrids 

 are not sterile, the fact gives increased reason for supposing these various 

 forms are merely local races, and not difi"erent species ; that if they are really 

 distinct species, division has not proceeded sufficiently far, because the 

 Gillaroo, a form of Trout with a thickened middle coat of the stomach, has 

 been termed Salmo stomachims Günther, whereas the Great Lake Trout 

 with a thickened stomach, and the Charr, having a similarly transformed 

 organ, have not yet been differentiated into species. Dr. Day considers that 

 all our non-migratory Freshwater Trout (excluding the Loch Leven) are 

 merely local races ; that interbreeding will produce mongrels, in which ste- 

 rility need not be anticipated, while introducing new races (unless on the 

 principle of preventing breeding in and in) will not be of much benefit to 

 fisheries , unless the food is in excess of local requirements, for if not, the 

 new-comers will revert to the colour, form and size of the original tenants 

 of the water. — 



