132 



cellaria scabra) it seems natural to suppose that these heterozooecia in this family 

 always have an inner wall of their own. In Caberea and Caberiella I have found 

 a septum dividing the vibracular chamber into two, of which only the distal 

 may contain the muscles. While the ooecia in the majority of this family are 

 hyperstomial, they are endozooecial and more or less deeply immersed in Bugu- 

 lopsis Peachi, Bugulopsis cuspidata, Menipea crystallina, M. cervicornis, M. Buski, 

 M. triseriata and M. spicata. In M. crystallina they are enclosed in kenozocEcia 

 with a large membranous frontal area, while in the othei-s thej"^ are immersed 

 in ordinary zooecia, in such a way, however, as to appear more or les promi- 

 nent on the zooecial surface. In M. Buski and M. cervicornis the distal part of 

 the ooecium is covered by a granular cryptocyst. In a smaller number of species 

 the ectoooecium is wholly calcified, e. g. in Scrupocellaria ternata^, Scrupocellaria 

 reptans and Scrap, scruposa, but in most cases a larger or smaller proximal part 

 is membranous and accordingly appears as a rounded or triangular area, clearly 

 distinguishable from the calcified distal part. This is seen e. g. in Caberiella 

 benemunita (PI. XXII, fig. 8 a), Menipea roborata (PI. II, fig. 7 a) and M. ligulata 

 (PI. II, fig. 8 a). 



This family is one of the most natural and most sharply delimited, and the 

 differences shown by the zooecia in respect to the armature of spines, develop- 

 ment of gymnocyst and cryptocyst etc., are all subject to such great variation 

 from species to species that no generic importance ought to be attached to them. 

 The division of the genus has therefore hitherto been based chiefly 6n the struc- 

 ture and appearance of the heterozooecia, and for the present I am unable to 

 delimit them in a more natural way. In earlier as well as in more recent times 

 attempts have been made to divide the large genus Menipea, e. g. by Gray, Mc 

 Gillivray and Waters. But as I considei* it superfluous to enter into a critical 

 examination of the genera Emma ''■ and Craspedozoum ^ proposed by the two 

 former authors, I shall limit myself to a closer examination of the divisions made 

 by Waters*. This author discusses the subject as follows: »In the description of 

 the species, it is now shown that in the Cellulariidae there are two distinct kinds 

 of articulation. In the larger number the new branch is given off from a small 

 chamber formed for the purpose. As the type of this section Menipea Buski is 

 figured (PI. I, fig. 10); and I propose to restrict Menipea to those forms having 

 this kind of articulation; and it will then include M. Buski, Mac G., M. crystal- 

 lina, Gray, M. cyatlms, Thompson, M. cervicornis, Mac. G., M. compacta, Mac. G. — 



' 111 this species which has hitherto been referred to the genus Menipea, I have found a vibra- 

 culum, but witliout flagellum. * 2, p. 27. " 69, p. 131. ' 111, p. 2. 



