1748 



THE VOYAGE OF H.M.S. CHALLENGER, 



latter (with the terminal coronets), and the anchor pencils, covering the surface of the 

 thicket and the mantle, seem to project over the surface of the calymma. The entire 

 form of the latter is therefore a symmetrical polyhedron. The phaeodium fills up a small 

 part only of the calymma, and is usually enclosed in the two galeae and their rhino- 

 cannfB (PI. 127, figs. 5, 9), but often also a part of the phasodium is scattered 

 around the oral half of the central capsule. 



Synopsis of the Genera of Ccelographida. 



I. Subfamily 



Ccelotliolida. 

 Rhinocanna of each valve with 

 two paired lateral frenula. 

 The distal ends of the - 

 dichotomous brushes are 

 not united by anastomoses, 

 and form an outer bi- 

 valved fork-thicket. 



Eight paired styles (four on each valve), 

 Twelve paired styles (six on each valve). 

 Sixteen paired styles (eight on each valve). 



11. Subfamily 



Coeloplegmida. 



Rhinocanna of each valve with 

 an odd sagittal frenulum. 

 The distal ends of the 

 dichotomous brushes are 

 united by anastomoses, and 

 form an outer bivalved 

 lattice-mantle. 



Mantle with six styles. 

 Mantle with 



/ One odd and two paired styles 

 ( on each valve. 



■ i.i. i 1 ( Two odd and two paired 

 eight styles. < , , u t 



° •' styles on each valve, 



■^T i.1 -ii. J. 11 ( One odd and four paired 



Mantle with ten styles. < . , i, i 



•' ( styles on each valve, 



,r .1 -ii . 1 .7 f Two odd and four paired 



Mantlewithtwelvestyles. < . , . , ^ 



'' I styles on each valve. 



Mantle with fourteen j One odd and six paired styles 



styles. 



on each valve. 



Mantle with sixteen ( Two odd and six paired styles 



styles. 



on each valve. 



731. GmlotJiolus. 



732. Coelothauma. 



733. Ccelothamnus. 



734. Gcelogi'aphis. 



735. CcelosjMtMs. 



736. Ccelodecas. 



737. Gmlostylua. 



738. Codoplegma. 



739. Ccelagalma. 



Subfamily 1. Ccelotholida, Haeckel. 



Definition. — Ccelographida with two paired lateral frenula on each galea, and 

 with free terminal branches on the hollow radial tubes, without an external lattice- 

 mantle. Eight to sixteen long styles are j^rominent over the surface of the fork-thicket, 

 which is composed of the caudal brush and the dichotomous basal branches of the styles. 



Genus 731. Ccelotholus,^ n. gen. 



Definition. — Ccelographida with two paired lateral frenula on each galea, 

 without external lattice-mantle, armed with eight styles (two pairs of styles on each 

 valve). 



1 Ccelotholus^Hollow cupola; xoiXoj, io'hos. 



