Lord Ho ire Island Polt/zoa. 387 



and to variety " uiunita," Hincks, which Mr. Waters records 

 from Port Phillip Heads and Green Point, New South Wales, 

 but there is not sufficient difference to warrant its being con- 

 sidered a distinct variety. It is apparently very common there, 

 for there were over a dozen specimens among the slides, and 

 all the fragments of shells, etc., with the exception of three, 

 were encrusted with it. 

 The new species are : — 



Thalamoporella howensis, nov. sp. (PI. Fig. 2). 



Zoaria encrusting. Zooecia elongated, sub-hexangular, with 

 distal margin generally rounded. Surface coarsely granulated 

 or jjerforated, except a space below the proximal margin of the 

 thyrostome. Margins raised and finely crenate. Thyrostome 

 (opesial) very large, arched above, irregular below, with a 

 shallow depression at each side and underneath it, in the centre, 

 an internal plate. 



A single specimen. This is a very puzzling form ; it seems 

 to be intermediate between Steganoporella and Thalamoporella. 

 The general appearance is that of the latter, but the projecting 

 plate under the cryptocyst (?) shows that the structure is very 

 similar to that of Steganoporella ; the plate possibly represents 

 the bottom of the " tube '" which is jjresent in that genus, and 

 if, as possibly may be the case (as it is not in perfect condition), 

 it had when alive a membranous covering, it would certainly 

 be relegated to that genus. 



Schizopopella gibberula, nov. sp. (PL Fig. 3). 



Zoarium encrusting. Zooecia ovoid, ventricose ; surface 

 covered with small tubercles which are connected with each 

 other by an irregular network of narrow raised lines. 

 Thyrostome large, orbicular, with a rounded sinus. An 

 avicularium with a pointed mandible on a large raised elevation 

 on one side. Ooecia globose, subimmersed ; siu^ace perforated. 

 This somewhat resembles S. cecilii in appearance, but the shape 

 of the thyrostome is different ; the sinus is rounded and 

 shallow, and there is an avicularium on a large umbo on one 



