250 Proceedings of the Royal Physical Society. 



By Professor Balfour. — From the Author. 2. Transactions of the Bo- 

 tanical Society. Vol. VI., Part III. Edinburgh, I860.— 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 — Ko- 

 niglichen. Geologischen Reich sanstalt, 1860. ' XL Jahrgang, Xo. 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. Steethill 

 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. 5 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 Granton. 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 Hydroidae, 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, 



