98 



10) The basal edge of the distal wall not angular; long-slalked 



fixed aviculaiia; no constriction dislally to the distal wall... EpisiomUi Fleming. 



9) Tlie zott'ciuni not divided into a {)roxinial, narrow cylindiical 

 and a distal wider part (no avicularia). 



11) The basal edge of the distal wall angular; (radical fibres issue 



from the lateral margin in the proximal jiart of the zoa>cium . . . (leiiicllarid Savigny. 



11) The basal edge of the distal wall not angular lirellid Dyster. 



8) 0(rcia present: 



12) The oa'cia, which do not issue from the boundary between two 

 zooecia placed in the same longitudinal row, are covered by kenozooe- 

 cia; (the proximal part of the zorecium separated from the distal by 

 a more or less distinct constriction a little distally to the distal wall). 



13) The ooecia are placed on zoa'cia of ordinary size; zoa'cia very 

 asymmetrical, from the narrow tube-like proximal part widening into 

 an obliquely funnel-shaped extremity, furnished with spines; as a rule 

 there are found avicularia, the radical fibres, which go down along 

 the l)asal surface of the colonj', issue from a rosette-plate a good way 



distally on the basal aspect of the zo(L'cia Conmcopina n. g. 



13) The ocecia are placed on zooecia of smaller size; zoa;cia sym- 

 metrical or only a little asymmetrical; no sj)ines; no avicularia. 



14) The basal edge of the distal wall angular; the oa'cia-bearlng 

 zooecia placed between two zoa'cia in a bifurcation; (the frontal wall 

 of the kenozooecium membranous, furnished proximally with two 

 calcareous ]irocesses; (no rosette-plate between two neighbouring 



zooecia Didijinia Husk. 



14) the basal edge of the distal wall not angular; the oa>cia- 

 bearing zooecia attached either j)roximally to the frontal area or to 

 the basal surface of other zocecia; the frontal wall of the kenozoa>cium 

 calcified Eucralea Lamouroux. 



12) Free oa^cia issue from the boundary between two zooecia placed 

 in the same longitudinal row: 



15) The distal wall furnished with four uniporous rosette-plates, 

 each of which is jjlaced at the bottom of a se])arate chamber; (no 

 avicularia) Dimclopia Busk. 



15) The distal wall not formed in this way: 



16) Each zoa»cium has a strong muscle, which at its distal end is 

 attached to the inner side of the external wall of the zoa'cium, and 

 at the other to a conical ])rojecti()n from the distal wall of the next 



