498 PROF. A. DENDY AND MISS L. M. FEEDERICK ON 
Register Nos., Localities, etc. VI. 17^, VI. lie, Sandy Isle; II. lb, 
III. 11, IV. 6, IV. 7, IV. 10, Wooded Isle. 
Reniera spp. 
There are also in the collection a number of more or less fragmentary 
specimens representing other species of this difficult genus. 
Register Nos., Localities, etc. I. 3, VII. 4/;^ Turtle Bay ; VI. 14, VI. 15 b, 
Sandy Isle. 
27. Peteosia DURA (i\Wd/o) Fo«mae?- [1887]. 
Meniera dura Naido. 
Reniera ? dura Nardo, Schmidt [1862]. 
Schmidtia dura Balsamo Crivelli [1863]. 
Schmidtia dura Schmidt [1868]. 
Petrosia dura Topsent [1897]. 
Petrosia dura Ferrar [1914]. 
Petrosia dura Babic [1921, 1922]. 
The single specimen in the collection consists of a somewhat irregularly 
shaped, digitiform fragment, 40 mm. long and 10 mm. thick, which had 
probably been growing erect and has evidently been cut off transversely from 
a larger sponge. The surface is smooth, and the dermal membrane, which 
is thin but distinct, is pierced by inhalant pores visible with a lens. There 
are two round oscula, 2 mm. in diameter. Colour in spirit light reddish 
brown ; texture hard but brittle. 
The skeleton arrangement and spicuiation agree closely with those of one 
of Schmidt's specimens in the British Museum. 
The spicules are oxea, which show a great tendency to become rounded off 
at one or both ends ; they measure about 035 by 0"015 mm. 
Freviously known Distribution. Adriatic (Schmidt, Babie) ; Mediterranean 
{Balsamo Crivelli, Topsent) ; Cantabrico (Ferrar). 
Register No. and Locality. VI. 16 a, Long Island. 
28. Halichondria phakellioides n. sp. (PI. 26. fig. 10.) 
The single specimen consists of a portion of an erect lamella, 190 mm. in 
height, 75 mm. in width, with a maximum thickness of 8 mm,, constricted 
towards the base of attachment so as to form a very short, thick stalk. The 
lamella, which has a narrow, very slightly sinuous margin, appears similar 
on both surfaces, but one has been somewhat cracked and rubbed. 
The surface is smooth and practically even; covered everywhere by a very 
thin, transparent dermal membrane (rubbed off in places), which contains 
numerous irregularly and looselj- scattered tangential oxea. The dermal 
membrane is dotted with numerous small, round pore-areas, the pores 
themselves apparently being closed. The oscula are very inconspicuous ; 
they may be represented by minute apertures at the apices of several small 
