March 18, 1887.] 



SCIEJSrCE. 



267 



If even the least significant of all of the facts 

 reported from England be accej)ted, we are left to 

 deal with an unknown something quite apart from 

 instinct, — something, for so it seems tome, which 

 cannot be compared with it in any way, but which is 

 the evidence of a higher order of brain-manifesta- 

 tion than we have yet met with. 



HOEATIO R. BiGELOW, M.D. 

 Leipzig, Feb. 28. 



The tail of Chlamydoselachus. 



A recent opportunity of examining a second speci- 

 men of Chlamydoselachus furnished the means of 

 adding an item or two to our knowledge of that 

 peculiar genus. In several points the example 

 differed from that originally described. This was 

 notably the case with the tail. On the later capture, 

 this organ was a little more than one-fourth of the 

 total length, and, with the vertebral column, tapered 

 to a sharp extremity ; whereas in the first one it 

 stopped abruptly, with vertebrae of considerable 

 size, as if truncate. On the new one, the lateral 

 line, with a few short breaks posteriorly, continued 

 to within an inch of the end of the tail. All this 

 indicates that the tail of that which served as the 

 type was deformed and incomplete : the deformity, 

 in all likelihood, being of embryonic origin. Pro- 

 portioned as the new one, the tail of the type would 

 have been seventeen inches long, instead of which it 

 was but little more than ten. Completed, the type 

 would have had a total length of sixty-six inches, to 

 a circumference of eleven and a half. The more 

 recent specimen had a length of forty-eight, to a 

 circumference of ten and a half inches, which made 

 it rather less slender and snake-like than its pred- 

 ecessor. 



Another difference occurred in the dentition, 

 which, in the last examined, showed variations in 

 the number of denticles between each lateral cusp 

 and the median : sometimes there were two, some- 

 times but one. 



The troiieic folds, abdominal keel, were present, 

 as on the specimen from which the original descrip- 

 tion was taken. S. Gakman. 



Cambridge, Mass., March 11. 



The Quebec group. 



Thinking it may be interesting to geologists to 

 learn the latest conclusions in reference to the strati- 

 graphical succession and distribution of the rocks in 

 the province of Quebec, hitherto known as the ' Que- 

 bec group,' I send you the following brief observa- 

 tions on this subject : — 



As is well known, the divisions made by my prede- 

 cessor, the late Sir W. E. Logan, of this interesting 

 and exceedingly complicated group of formations, 

 were in ascending order, — Levis, Lauzon, and Sil- 

 lery, — - and these together were supposed to represent 

 a peculiar phase of the calciferous and chazy for- 

 mations of the New York lower jDaleozoic series. I 

 have elsewhere made known as the result of personal 

 investigation that portions of several systems and 

 formations had evidently been included in the Que- 

 bec group as described in the ' Geology of Canada, 

 1863,' and depicted on the geological map of Canada, 

 published in 1866. During a personal examination 

 of a large portion of the area during the seasons of 

 1876, 1877, and 1878, I recognized strata which I 



considered clearly belonged to systems and forma- 

 tions ranging from pre-Cambrian to Silurian ; and 

 also that much of the so-called ' Sillery ' was in 

 reality not the youngest, but the oldest member of 

 the groiip, and of pre-Cambrian age. 



All subsequent investigation has confirmed the cor- 

 rectness of these conclusions, first advanced in a 

 paper read before the Natural history society of Mon- 

 treal in February, 1879, and more fully treated in re- 

 ports and papers since published in 1880, 1883, and 

 188-1. Since the date of the last of these publica- 

 tions, considerable additional information relating to 

 the distribution of the several formations has been 

 acquired ; and I now find that no less than four dis- 

 tinct horizons can be recognized, each of which is 

 marked by important bands of conglomerate. Three 

 of these (Nos. 2, 3, and 4) are fossiliferous limestone 

 conglomerates, while one (No. 1) is chiefly felspathic 

 and dioritic, is non-fossiliferous, and generally pre- 

 sents the appearance of a volcanic agglomerate or 

 breccia, which in places becomes a brecciated ser- 

 pentine, or is otherwise variously altered, and is often 

 schistose and micaceous, — pre-Cambrian. 



No. 2 is of Cambrian age, and is best seen along 

 the south shore and at the north end of the Island of 

 Orleans, at Bic, at Metis, and at several points lower 

 down, on the south side of the St. Lawrence Gulf. 



No. 3 is the celebrated Levis conglomerate, well 

 exposed at Point Levis and at the south-west end of 

 the Island of Orleans. It is interbedded with gray 

 and dark blue highly graptolitic slates, recognized 

 by Professor Lap worth as marking the phyllograptus 

 zone of Europe. It also recurs with its associated 

 phyllograptus slates at several points between Metis 

 and the Marsouin River on the south shore of the 

 St. Lawrence, always in discordant contact with the 

 strata of the preceding group. 



No. 4 is the limestone conglomerate of the Quebec 

 Citadel Hill. It occurs there in three or four more 

 or less lenticular beds, none of which exceed six 

 feet in thickness : they are associated and interbedded 

 with black highly carbonaceous and graptolitic strata, 

 yielding a valuable cement-stone. Both to the north- 

 east, before reaching the Island of Orleans, and to 

 the south-west, these beds are cut off by the curving 

 line of the great St. Lawrence and Champlain or 

 Appalachian fault, and are brought into abrupt con- 

 tact with the red and greenish gray slates of No. 2. 

 They appear again, however, on the south side of 

 the St. Lawrence near St. Antoine, and thence pass 

 beneath the drift-covered level country to the south- 

 west. I believe these beds to be a part of the Utica, 

 Hudson River, or Lorraine group. Professor Lap- 

 worth, who has recently examined the graptolitic 

 fauna from these rocks, considers it to denote a stage 

 older than Trenton limestone, but decidedly newer 

 than the Levis phyllograptus zone. The latter view 

 is entirely in accord with the stratigraphical evidence 

 as first published by me in 1879 ; but, so far as the 

 stratigraphy is at present known, it is as decidedly 

 opposed to the former conclusion. Lists by Pro- 

 fessor Lapworth, of the graptolites f rom the different 

 horizons above named, will appear in the volume of 

 the Transactions of the Royal society of Canada, 

 shortly to be published. 



The fauna of No. 2 conglomerate, as well as that 

 of the associated slaty and shaly beds, is exclusively 

 of Cambrian type, — Dictyonema sociale, Eophyton 

 Linneanum, Cruziana (?) Paradoxides-Archaeocya- 

 thus, etc. 



