MR. B. M'^LACHLAiST ON A MAEINE CADDIS-FLY. 417 



varieties or local races, and mongrels are tlie result. Conse- 

 quently sterility need not be anticipated ; but, on the contrary, 

 improvement is more likely to ensue (should there be no defi- 

 ciency in food) than when the stock is bred in and in. 



It also tends to show that where small, but not malformed, 

 breeds of trout exist, riparian proprietors had far better investi- 

 gate the condition of the food-supply and nature of the waters 

 in their streams than rely upon the introduction of larger races. 

 They may be assured that the Gillaroo, when it cannot obtain 

 shellfish, will in time lose its thickened stomach ; and descendants 

 of the various malformed varieties which I have alluded to will 

 revert to common brook-trout — that, in short, sooner or later 

 new stock will become indistinguishable from the original local 

 breed in colour, form, and size. 



On a Marine Caddis-fly (Philanisus, 'Waiker, = AnomaIosfoma, 

 Brauer) from New Zealand. By E. M^Lachlan, F.E.S., 

 r.L.8., Hon. Memb. N.-Z. Institute. 



[Eead June 15, 1882.] 



In April of this year I received a letter from Prof. F. "W". Hutton 

 of Canterbury College, Cbristchurch, New Zealand, in which was 

 the startling announcement that tlie larva of a Caddis-fly lives 

 habitually in rock-pools, hetweeii liigh and low loater-marlxs, in 

 Lyttleton Harbour in that colony, and forms its case of coral- 

 line seaweed. He had often attempted to rear the perfect 

 insect, but only once succeeded, and then when he was away 

 from home ; so that only the dead remains were obtainable*. 

 Prof. Hutton gave me the welcome intelligence that these re- 

 mains, with larva and case, were on their way to this country in 

 charge of a friend who was coming home. This gentleman (Mr. 

 C. C. Bowen, Grovernor of the Canterbury Province) recently 

 arrived, and the materials are now in my hands. 



"We are so accustomed to associate Caddis-worms with fresh 

 water, that the arrival of these materials was awaited by me with 

 not unnatural impatience. We are already acquainted ^\ ith a 

 terrestrial species {Enoicyla); but no truly marine form had 



* A short notice to this effect was published by me in the ' Entomologist's 

 Monthly Magazine,' vol. xviii. p. 278 (May 1882). 



LINN. JOrnN. — ZOOLOGY, VOL. XVI. 31 



