250 Proceedings of the lioyal Physical Society. 
By Professor Balfour. — From the Author. 2. Transactions of the Bo- 
tanical Society. Vol. VI., Part III. Edinburgh, 1860. — From the Society. 
3. On the Tertiary Deposits associated with Trap -Rock in the East Indies. 
By the Rev. Stephen Hislop. — From the Author. 4. On the Arrange- 
ment of the Muscular Fibres of the Ventricular Portion of the Heart of 
the Mammal. By James Pettigrew, Esq. — From the Author. 5. The 
Quarterly Journal of the Geological Society. No. 62, May 1860. Vol. 
XVI., Part II. — From the Society. 6. Jahrbuch der Kaiserlich — Kd- 
niglichen. Geologischen Reich sanstalt, 1860. XI. Jahrgang, No. I., Jan., 
Feb., Marz. Wien. — From the Imperial Geological Society of Vienna. 
The Communications read were as follows : — 
I. Observations on British Zoophytes and Protozoa. 
On Atractylis palliata and coccinea (new species). By T. Strethill 
Wright, M.D. 
1. Atractylis palliata^ n. sp. PI. XI. fig. 6. 
Polypidom creeping, closely reticulate. Polyps fusiform, 
shortly stalked, minute, white, with eight alternating 
tentacles ; body of polyp clothed with a thick layer of 
' colletoderm/ Free medusoids springing from meshes of 
polypary, with four-lipped peduncle ; four lateral canals ; 
two long marginal tentacles and two tentacular tubercles 
alternately placed. 
This zoophyte was found on a shell inhabited by Pagurus 
Bernhardus, at Gran ton. When first observed, its closely- 
set and dense white polyps, surrounded by their gelatinous 
envelopes, were mistaken for a mass of minute ova. These 
envelopes cover the whole of the body of the polyps up to 
the border of the mouth, and consist of an exaggerated 
development of the gelatinous coat which probably exists 
on the polypidom and body of all the Hydroidse, in some as 
a delicate epidermis, in others (as in Bimeria vestita and 
the subject of this notice) as a thick, imputrescible coat — 
the " colletoderm." 
The Medusoids (PI. XI. fig. 7) are of great size when 
compared with the very minute polyp, and resemble exactly 
those of Atractylis repens, I have not witnessed any fur- 
ther development in them after their separation from the 
zoophyte. In those of A. repens, when kept alive for some 
time, the two tentacular tubercles put forth short tentacles. 
