352 Alexander Goodman More. [ie87 



count rings of tail. Thompson's largest Hibernicus weighed i Ib. 

 and 3 oz. 



Of head and body length was 1 1 inches 

 Of tail (imperfect) 8 ,, 3 lines 



Of ears 10^ lines 



which seems to show they vary in length. Please collect and study all 

 the information you can ; but do not at present write anything to 

 " The Zoologist " about the length of tail. By taking time you will be 

 likely to obtain some good results. Your list, T am glad to see, is in 

 the "J. of Bot." for January. 



(January idth.] I am glad to hear that Mus hibernicus is in such 

 good hands. Thompson seems to have seen the M. Rattus as well as 

 his M. Hibernicus from Ireland ; but he also speaks of a black variety 

 of the Common Rat. That I suppose will be the end of M. hiber- 

 nicus = a melanic form of M. decumanus. 



(February qth.} Your queries are not easy to answer. Of course 

 you must not offer a reward for specimens, nor in any way abet or 

 incite to the shooting of Sand-grouse, which I am sure, as an orni- 

 thologist, you would never think of. I think your best plan will be to 

 ask generally do any of your correspondents see or hear of any small 

 flocks of brownish-coloured birds frequenting the more inland parts of 

 the sand-hills. If seen away from the shore, likely such may be Sand- 

 grouse. I do not understand whether all or most of those seen this 

 winter were remainders of the spring immigration or fresh arrivals. 

 In some cases, if you are not afraid of inviting answers such as the 

 correspondent thinks would please you (a too common, and good- 

 natured fault in Ireland), you might copy out or abridge from Yarrell a 

 description, and, especially, send a tracing on transparent paper of 

 some plate or figure, and ask them to look on the ground for any trace 

 of the very small footmarks. And do not let them think it is a shore- 

 frequenting bird you are asking after. 



This correspondence, doubtless, did much to expedite, 

 amongst other matters, the settlement of the "Irish Black 

 Rat" question (by the conjoint inquiry of Messrs. Eagle 

 Clarke and Barrett-Hamilton), which, almost dormant 

 since Thompson's time, was re-opened in 1889, when 

 Harvie-Brown and Buckley's " Fauna of the Outer Heb- 

 rides " was published. The number of varying opinions 

 held regarding the animal which had been so little studied 

 is very curious. Thompson had thought it a distinct species, 

 but closely allied to the old English Black Rat (Mus rattus). 

 Bell had supposed it only a variety of Mus rattus. Mr. 

 Eagle Clarke, in some remarks which appeared in the 



