86 Bastian^ on the so-called Pacchionian Bodies. 
margin; stauros broad, dilated, reaching to the margin. 
Length -0036". (Fig. 32.) 
St. scaphul(Bfo7^miSj Grev. MS.; Dr. L. Lindsay. ^ Journ. 
Linn. Soc./ vol. ix, p. 134 (name only). 
Hab. Otago, New Zealand, in fresh water; Dr. Lander 
Lindsay. 
Very similar in general appearance to the diatom figured 
by my friend Dr. Lewis,"^ as a variety of St. Legumen, of 
Ehrenberg; but it differs in having a very broad, dilated 
stauros, instead of a very narrow, simple one; and in the con- 
traction of the valve below the apices. 
On the so-called Pacchionian Bodies. 
By H. Charlton Bastian, M.A., M.B. Lond., F.L.S. 
(Communicated by W. H. Ince, E.L.S.) 
(Read March 14th, 1866.) 
Certain granulations or minute polypoid excrescences in 
connection with the membranes of the human brain, now 
familiar to so many anatomists and pathologists, were first 
described in 1705 by Antonius Pacchionius,t and regarded by 
him as rounded glands, secreting a clear pellucid fluid, from 
which lymphatics proceeded to the pia mater. Succeeding 
anatomists, for a time sharing in this opinion, spoke of them 
as ' Pacchionian glands,^ and by this name they were known 
till a comparatively recent period, when a growing doubt as 
to their nature gradually resolved itself into a pretty firm 
conviction that they had no real claims to be included in the 
category of glandular structures. Now almost all anatomists 
prefer to speak of them as ^Pacchionian bodies.^ 
Although these growths have received a very fair share of 
attention since the date of their first discovery, still many of 
the statements made concerning them are quite conflicting, 
and the accounts to be found in English text-books more 
especially are meagre and inexact as to their real nature and 
mode of origin. Seeing that they are found in several situa- 
* " On extreme and exceptional variations of Diatomacese in some White 
Mountain localities," &c. By T. W. Lewis, M.D. 'Proceedings of the 
Academy of Natural Sciences of Philadelphia,' Jan., 1865, pi. 2, fis:. 14. 
t Dissert. Epistolaris de Gland, conglobatis durse meningis Humanae, 
indeque ortis Lympliaticis ad Piara meningem productis. Reprinted also at 
p. 103 of his 'Dissert. Physico-Anatom. de dura meninga Humana.* 1721. 
