36 



The Ottawa Naturalist 



[May 



stock are placed under Porilockia McCoy, which is 

 emended with subgeneric rank to receive them. 



(5). The other Phacopid stock is that of the 

 group of Phacops glocl^eri Barrande. Phacopidella 

 Reed is now restricted to it. This confines it to the 

 later Silurian stratigraphically and to the Tethys 

 (Bohemia) realm geographically. Wedekind's 

 generic name of Clocf^eria, also applied to this 

 group, is untenable, being preoccupied by Phacopi- 

 della Reed. 



1819. 

 1839. 



1843. 



1846. 

 1852. 

 1855. 



1864. 

 1880. 

 1893. 

 1905. 



1911. 



1913. 



1913a 



REFERENCES. 



McMurtie, Sketches of Louisville and the 



falls of the Ohio, Louisville, 1819. 



Emmrich, H. F., De Trilobites. Dissertatio 



petrofactologica, etc., Berolina, 1839, 56 pp., 



1 plate. 



Goldfuss, A., Syst. Ubersicht der Trilobiten, 



Neues Jahr. Min., etc., 1843, pp. 537-567, 



pis. 4-6. 



McCoy, Frederick, Silurian Fossils Ireland, 



Dublin, 1846, 72 pp., 5 p!s. 



Barrande, J., Systeme Sil. Centre de la 



Bcheme, vol 1, XXX, 935, pp., 51 pis. 



Sedgwick, Adam, and McCoy, Frederick, 



British Pal. Rocks Foss., London, 1855, 



830 pp., 25 pis. 



Salter, J. W., Mon. British Trilobites, Pal. 



See, 1864, 224 pp., 30 pis., text figs. 



Hoernes, R., Jahr. Geol. Reichsanst, Wien, 



Bd. 30, Heft 4 (1880), pp. 651-686. 



Vogdes, A. W., Bibliog. Pal. Crust., Occas. 



Pap., Cal. Acad. Sci., No. 4, 1893, 412 pp. 



Reed, F. R. C, The classification of the 



Phacopidae, Geol. Mag., (5), 2, pp. 172- 



178, 225-228. 



Wedekind, R., Klassifikation der Phaco- 



piden, Zeitschr. Deutsch, Geol. Ges., 1911, 



63, pp. 317-336. 



Clarke, J. M., Foss. Dev. do Parana, 



Mon. Serv. Geol. Min. do Brasil, vol 1, 



353 pp., 27 pis. 



Raymond, P. E., Trilobita in Zittel-East- 



man Textb. Pal., 2nd ed., vol. 1, pp. 692- 



729, text figs. 



INSTINCT MINUS EXPERIENCE. 



The more we study nature the more obvious it 

 becomes that the mysterious intuition called instinct 

 is not as perfect as some of the old school observers 

 imagined. Just what this inherited memory is we 

 are as far from thoroughly understanding as ever; 

 but study, observation and experiment are bringing 



to light some of its limitations. We know that it 

 does not spring into being, perfect and complete, 

 like Minerva fully armed from the head of Jove, 

 but is often only a startmg point, a suggestion or a 

 natural aptitude requiring experience and practice 

 for the full development of its possibilities. This 

 was admirably illustrated by a nest built by a pair 

 of Baltimore Orioles in a garden in Ottawa South 

 last spring. 



The nest was hung from near the end of a long 

 horizontal bough of Manitoba maple. When first 

 started the nest was some ten or twelve feet from the 

 ground, but the subsequent weight of the foliage 

 brought it down until almost within reach of the 

 hand and with the added weight of the first rain, 

 it almost trailed on the ground ; whilst a twist given 

 to the branch by unequal loading spilled out the 

 contents. The nest itself was very shallow and so 

 poorly constructed that it could be seen through in 

 every direction and the contained eggs were visible 

 from below. Attempts were made to prop up the 

 branch and correct its twisting but without effect 

 and after three eggs had been spilled out as fast as 

 deposited the nest was deserted. 



The illuminating part of the episode lay in the 

 fact that this pair seemed to be young birds and 

 probably this was their first attempt at nest building. 

 The male was certainly a yearling as was indicated 

 by his dull colour. The age of the female could 

 not be ascertained by her plumage, but her associa- 

 tion with a juvenile mate makes it probable that 

 she too was m her first breeding season. 



To these familiar with the beautifully woven and 

 deeply pocketed Oriole's structure hung from the 

 pendant tips of high flexible branches, this slovenly, 

 ill-judged nest is a curiosity. Fundamentally it fol- 

 lowed oriole tradition but in execution it violated 

 every principle of oriole construction. It was hung 

 from a horizontal instead of a pendant branch ; it 

 was shallow instead of being deeply pocketed, and 

 thin and open instead of being thick and densely 

 woven and indicated that whilst the inherited ideal 

 was there the fault lay in poor judgment and the 

 lack of technical ability. It is to be regretted that 

 absence from the city prevented the observer from 

 discovering where the new nest, that was immediately 

 started, was located and comparing it with the first 

 abortive attempt to see what advance in skill, if 

 any, had been made, and what had been learned by 

 expe'ience. 



P. A. Taverner. 



Geological Survey, 



Ottawa, Ont., Aug. 10, 1918. 



