432 Correspondence— H. I&hiJwra — Br. C. Callairay. ' 



first free and is only later enclosed in the periderm. The virgula 

 is single, and is not continuous throughout the whole length of the 

 polyjsary, since it undergoes two diiferent phases of formation. 

 The proximal part develops as a spine from the apertural part 

 of the sicula, whilst the distal portion is a prolongation of the 

 apex of the sicula. The virgula is united to the bases of the 

 partition walls between the thecas in some cases, but it is 

 frequently fiee for a great part of its length. Th^re is no double 

 longitudinal septum in the pol3'pary. 



As regards JJonograptus, the structure closely resembles that of 

 the Diplograptidfe. In Monograptus, however, there is only one row 

 of thecEe, which develop on the same side as the first theca. Unlike 

 Uiplograptus the thecse develop only in a distal direction. The distal 

 portion of the sicnla grows simultaneously with the thecse lying at 

 the same level. The virgula is somewhat triangular in shape and 

 lies on the inner side of, and occasionally in, the periderm itself, 

 not in a groove on the outer edge. No lumen to the virgula has 

 been observed either in Monograptus or in the Dij)lograptid£e, but 

 it is the opinion of the author that such existed and that it was 

 filled with a living substance. 



E. M. K. W. and G. L. E. 



ooI^I^:H]s:F'035^I^:E;3S^o:B- 



INTEEESTING CONTACT-METAMORPHISM. 



Sir, — I have read with much pleasure Mr. W. M. Hutchings' 

 article on " An Interesting Contact-Metamorphism," in the Geo- 

 logical Magazine for last March. There is one thing, however, 

 which I cannot understand anywise. It is the woi'd "anthrophyllite." ' 

 It seems to me to be a name applied to a mineral produced by the 

 contact-metamorphism. I know the mineral " anthophyllite," but 

 not "anthrophyllite."^ I have met with this term for the first time. 

 I inquired into nearly all mineralogical and lithological books our 

 University possesses, but all in vain. Would you, sir, kindly describe 

 it to me, or tell the literature, if any ? I beg this of you, or of 

 Mr. Hutchings himself. 



Geological Institute, Science College, H. Ishihara. 



Imperial University, Tokyo, Japan. 

 1st July, 1895. 



METAMORPHISM AT MALVERN. 

 Sir, — Would you permit me to add three words to the letter 

 which you kindly inserted in this month's Geological Magazine ? 

 In stating an analogy between the roasting of meat and the process 

 of metamorphism at Malvern, I wrote, or, at any rate, meant to 

 write, "The cook is able to observe the cause o/the change, and so 

 can the geologist at Malvern." In the letter as printed, the words 

 in italics do not appear. The omission is a vital one. 



Wellington, Salop, August, 1895. C. Callawat. 



^ No doubt Mr. Ishihara is correct : the r was an error in j)rintiug and should 

 have been deleted. — Edit. Geol. Mag. 



