Art. XVI. — Description of New or Little Knoivn Polyzoa. 



Paet XIII. 



By P. H. MacGillivray, M.A., M.R.C.S., F.L.S. 



(With Plates IV and V.) 

 [Read November 14, 1889.] 



NOTAMIA GRACILIS, McG. 



Zooecia very long and slender, aperture occupying almost 

 the whole of the anterior surface, rounded or quadrate 

 above, and with the superior margin projecting slightly 

 forwards ; a pedunculate, capitate avicularium on one or 

 both sides, from the upper part of the posterior tube. 



In a paper read before the Society in November 1885, I 

 briefly described a species as Galwellia gracilis, from one or 

 two very imperfect fragments, believing it to be a species 

 indicated, but not described, by Mr. Maplestone. This 

 identification is, however, somewhat doubtful, as I have on 

 several occasions had specimens sent to me named G. gracilis, 

 which proved to be merely rather slender forms of the well 

 known C. hicovnis. After my brief and necessarily 

 imperfect description was published, I received from Mr. 

 Whitelego-e some fracrments on an alofa from Port Jackson, 

 as well as specimens mounted in balsam. These have 

 enabled me to make out its real structure, and to confirm 

 Mr. Whitelegge's opinion, that it belongs to the genus 

 Notamia. 



Notainia gracilis is at once distinguished from the only 

 other species, the European N. bursaria, b}- its much 

 smaller size, the slenderness of the zooecia, the rounded or 

 somewhat quadrate form of the upper part of the aperture 

 and its projection forwards, and the more slender attach- 

 ment of the avicular-ia to the posterior tube, which also is 

 not enlarged to the same extent above. 



Stirparia exilis, n. sp., PI. IV. 



Zoarium very small, fiabellate, branches dichotomously 

 divided. Zooecia alternate, elongated, upper edge straight, 



