Correspondence — G. W. Lamplugli. 575 



•overgrown and concealed in the adjacent woodland. I found after- 

 wards that most of the Iron-sand fossils preserved in the Geological 

 Survey Museum at Jermyn Street, collected many years ago, are 

 labelled " Combe Wood," and are in all respects like those which 

 I obtained from the wall ; they were probably got when the quarry 

 was open. This flaggy iron-grit may possibly form part of the 

 supposed Purbeck deposit of Combe Wood described by Fitton and 

 mentioned by Professor Phillips, though more probably it has been 

 obtained from the sands just above that horizon. 



I was able to devote only a very short time to the examination 

 of the material, but noticed that the fauna, though rich in individuals, 

 was scanty in species. A more thorough investigation is, however, 

 highly desirable, especially as the relation of this fresh - water 

 fauna to the marine Lower Grreensand stands in great need of 

 elucidation. G. W. Lamplugh. 



Bridlington Quay. 

 November Uh, 1902. 



' CALCKETE.' 



Sir, — " Murder will out," whether of person or language, and the 

 appearance in the October number of the Irish Naturalist of a new 

 word for which I am responsible makes requisite an open confession. 

 The word is ' calcrete,' applied in this instance by a friend who has 

 become accustomed to the term through our conversation, and has 

 trustfully used it as a ' good ' word in describing the shelly drift- 

 gravels near Dublin. The indiscretion will be repeated, by my 

 colleagues as well as myself, in the forthcoming new edition of the 

 Geological Survey Memoir on the neighbourhood of Dublin, and 

 preliminary explanation and definition seems therefore desirable. 

 In the drifts around Dublin, as in most places where in like manner 

 limestone-debris enters largely into the composition of the superficial 

 deposits, the sand-and-gravel beds are often cemented sporadically 

 into hard masses by solution and redeposition of lime through the 

 agency of infiltrating waters. In order to indicate this condition 

 on the field-maps a terse expression was sought to replace such 

 long and awkward circumlocutions as ' conglomerated gravel,' 

 ' calcareous concreted gravel,' etc., and for this purpose the 

 abbreviation 'calcrete' was invented and found adequate. Other 

 workers under similar conditions may find the word equally 

 serviceable, and to them I therefore recommend it. 



Moreover, I have the hardihood to suggest that the term might 

 be complemented by equivalents, — ' silcrete,' for sporadic masses in 

 loose material of the ' grey wether ' type, indurated by a siliceous 

 cement ; and ' ferricrete ' when the binding substance is an 

 iron - oxide. I will grant that these terms are etymologically 

 somewhat imperfect, but the inconvenience of an additional syllable 

 would be a more weighty objection where expressive brevity is of 

 prime consequence. G. W. Lamplugh. 



Bridlington Quay. 

 November ith, 1902. 



