Prof. H. L. Hawkins—Echinoids from Shenley Hill. 57 
Note on a Collection of Echinoids from the Limestone- 
lenticles in the Sand-pits of Shenley Hill. 
By Hersert L. Hawxins, D.Sc., F.G.S8., Professor of Geology, 
University College, Reading. 
we the request of Mr. H. Woods, F.R.S., I have examined a small 
series of Hchinoids belonging to the Sedgwick Museum, 
Cambridge, collected by the late J. F. Walker from the sand-pits 
on Shenley Hill, near Leighton Buzzard. Mr. G. W. Lamplugh 
has sent me four additional specimens from the same locality. The 
matrix seems to be the same in all the examples except D, and agrees 
absolutely with a sample of the Limestone-lenticles sent for com- 
parison by Dr. F. L. Kitchin. The age of this Limestone is a subject 
of controversy (see Grou. Mac., January—March, 1920), and a critical 
analysis of its fauna seems the only means of deciding the issue. 
Unfortunately, most of the Echinoids are very indifferently preserved 
so that specific determination is often doubtful, and in some cases 
impossible. 
Twenty-four specimens were submitted to me by Mr. Woods, and 
I have placed numbers on the boxes in which they were sent. Under 
those numbers they are referred to here. The following is the list 
according to my determinations :— 
. Internal mould of ? Peltastes or ? Salenia. 
. Internal mould of ? Psewdodiadema or ? Diplopodia. 
‘* Pyrina’’ sp. nov. (? nov. gen.). 
Pyria sp. 
. Internal mould of Pyrina sp. 
. ef. inflata d’Orbigny. 
. ef. desmoulirsi d’ Archiac. 
. ef. desmowlinsi d’ Archiac. 
. aff. levis Agassiz. 
. sp. (or spp.). Two specimens. 
. aff. levis Agassiz. Two specimens. 
. aff. levis Agassiz. 
13. Catopygus columbarius Agassiz. Two specimens. 
14. Nucleolites lacunosus Goldfuss. 
15. ‘‘ Echinospatagus’’ aff. murchisonianus (Mantell). 
16. Internal mould of ? Cardiaster or Holaster. 
17. Internal mould of ? Cardiaster or Holaster. 
18. Indeterminable Echinoid fragment. 
19. Cardiaster ? latissimus Agassiz. 
20. C. ef. fossarius (Benett). 
21. C. ef. fossarius (Benett). 
tty ty ty ty ty ty 
Mr. Lamplugh’s specimens are — 
A. Internal mould of Pseudodiadema (? No. 2 above). 
B. Obscure specimen (? same form as A). 
C. ? Cardiaster sp. Two very small specimens. 
D. Mould and counterpart of C. aff. latissimus Agassiz (see note below). 
A few critical notes on some of the specimens are now given, 
and apologies are due for their scanty character; but pressure of 
academic work denies opportunity for prolonged research at the 
