BRYOZOA 4 3 



in the middle, being irregular in shape, sometimes bifurcate. The area is larger than that 

 of Lepraha thyreopora (Busk), to which however it is most nearly related, though possibly 

 Hincks is not correct in uniting Busk's species with M . Malusii Aud. and speaking of it as 

 a very important variation. 



There lias been a tendency to create too many varieties of the common M. Malusii, and 

 M. ciliata, even where there are considérable différences, which in other cases would hâve 

 been thought sufficient for spécifie séparation. Hincks considérée! the range was very great, 

 and we certainly find graduai change ofthe number and position of the pores, showing how 

 impossible it is to place much reliance on the surface pores for generic division. 



On the other hand, Jtjllien and Neviani would make the shape of the suboral pore 

 of generic value, proposing several new gênera based on the shape ofthe pore. Very closely 

 related to the Malusii and decorata group there are forms, in which the pore takes quite différent 

 shapes, and I cannot follow Neviani in ail the divisions he makes. 



The Microporella Malusii, var. innbonata MacG. has ovicelligerous cells with apertures 

 double the width of those of other zoeecia, and in a spécimen sent me as Microporella violant; , 

 from Guernsey the ovicelligerous zoeecia are much the largest having three or more médian 

 pores, while the ordinary zoœcia hâve uniformly two médian pores. This is doubtless the 

 var. i. of Hincks, and in the Paris Muséum there is a spécimen from Baie de Cadiz, 

 3o mètres, dredged by the Talisman ; also in the British Muséum there is a similar one named 

 M. violacea. It would belong to the genus Heckelia of Neviani, and it may be that in M . Malusii, 

 var. innbonata and this violacea we hâve the commencement of characters now become gênerai 

 in Adeonella. 



Habitat. — M . Malusii seems to be quite cosmopolitan : the variety thyreopora is also 

 widely distributed, and Malusii has been found fossil in the Tertiaries of Europe and Australia. 



Exp. Antarct. Belge. 



N os i3g, 140. Porto Torro, Ile Navarin, Magellanes, Chili. Jan. 3 rJ , 1898. 



Microporella parvipora sp. nov. 



(PI. III, fig. 23, 6) 



Zoarium adnate. Zoœcia ovate, distinct, near the distal end and border small pores, 

 which do not seem to be stellate. Oral aperture arched above, straight below, with 6 oral 

 spines. Médian pore crescentic, placed above the middle of the zoœcium. 



This in gênerai appearance much resembles M . Malusii Aud., but differs in having small 

 zoœcia, and much smaller aperture, also the pores are smaller and not stellate. In the spécimen 

 drawn 1 could not distinguish any oral spines, but found them in some others. 



In the British Muséum there is a Microporella from Tierra del Fuego, which is either 

 this species or is closely allied to it, though the médian pore appears to be much larger, but 

 the spécimen being worn the chajacters are not very clear. From New Zealand I hâve a 

 spécimen with large crescentic pore, with internai denticles, but without stellate pores, and this 

 no doubt is M. parvipora. In the d'Orbigny collection it occurs from the Falkland Islands, 

 N° 13676. 



