Qeohgical Society. 207 



of its peculiar tentacles. It is, of course, quite possible that 

 such have been overlooked, especially in view of the fact 

 that so few of the Cestodes known to science have been 

 examined iu a living condition. Their extreme retractility, 

 amounting almost to disappearance, would render it most 

 easy to miss them in sections through the scolex. I have 

 myself been unable to discover them in sections of Rhab- 

 dometra cylindricn. If this lack of tentacles is only apparent 

 and due to the difficult)'' of seeing them, it may be that this 

 worm is identical with Rhabdometra numida, a species 

 descril)ed by Fuhrniann from the Guinea-fowl N. jjtilo- 

 rhyncha*. While therefore I believe myself to be correct in 

 describing the worm as a " new tentaeulate Cestode," it may 

 not be a new Cestode. But further investigation is required 

 before it can be asserted that the existence of retractile 

 tentacles is characteristic of the genus Rhabdometra^ and, for 

 the matter of that, of other genera. 



PROCEEDINGS OF LEARNED SOCIETIES. 



GEOLOGICAL SOCIETY. 



November lOtli, 1919.— M:r. G. W. Lamplugh, F.R.S., 

 President, in the Chair. 



The following? communication was read : — 



"O 



' Tlie Pleistocene Deposits around Cambridge.' By Prof. John 

 Edward Marr, Se.D., F.K.S., V.P.G.S. 



This paper deals with the deposits in the immediate vicinity of 

 Cambridge, and contains new recoi'ds of sections, fossils, and imple- 

 ments. It is pointed out that, owing to alternating periods of 

 erosion and aggradation, relative height above sea-level is not a 

 trustworthy index of antiquity, and modifications of the classilication 

 proposed by W. Penning and A. J. Jukes-Browne are indicated. 



The Author suggests the following chronological sequence, in 

 descending order: — 



Feet. 



(1) Barnwell Station Beds 20 



(2) Newer Downinf? Site Beds 35 



(3) Newer Barnwell Village Beds 45 



(4) Huntingdon Road Clays 70 



(5) Observatory Beds 85 



(6) Corbicula Gravels (Barnwell village, etc.) ... 30 



* Swedish Zool. Exp. E^'ypt, i)t. iii. 1!)09, p. 3<j. 



