fea 
D.P. GORDON AND P.D. TAYLOR 
Figs 51-54 Onychocellid cheilostomes. 51-52, Chondriovelum fossilis sp. nov.; 51, IGNS BZ 188-4, branch fragment; notice reticulation of cryptocyst, 
x 211; 52, IGNS BZ 188-5, vicarious avicularium, x 162. 53-54, Ogiva incompta sp. nov., IGNS BZ 189-1, holotype, part of large colony fragment 
showing disposition of autozooids and vicarious avicularia, x 41 and x 87 respectively. 
respectively (Moyano 1974; Hayward & Thorpe 1988). In this genus 
the avicularium also has both rostral and opesial foramina, although 
they tend not to be regular in shape. 
There are some similarities with the monotypic Antarctic 
aspidostomatid genus Larvapora Moyano in the form of the orifice 
and the vicarious avicularium. Larvapora mawsoni (Livingstone) 
has folded bilamellar colonies, however, projections from the distal 
rim of the orifice, and elevated rostral rims. It also has distinctive 
