PLATE III. 
Fig. 1. Homceosolen virgulosus, Greg. Middle Chalk — Zone of 
Micraster cortestucUnarium : Chatham. Reverse face of 
the zoarium, showing the lateral processes ; x 8 dia. 
Gamble Coll. [D. 395.] 
Fig. 2. Trochiliopora humei^ Greg. Middle Chalk ; ? Gravesend. 
Fig. 2«, the type-specimen from the side, x 3 dia. ; 
Fig. 26, the upper surface of the same specimen, - x 3 dia. 
? Bowerbank Coll. [D. 2995.] 
Fig. 3. Semicytis rugosa, d’Orb. Middle Chalk — Zone of Micraster 
cortestudinarium : Chatham, Fig. 3«, the obverse surface 
of a stem, with somewhat irregular pinnules, x 11 dia. ; 
Fig. 36, the reverse surface of the same specimen, x 11 dia. 
Gamble Coll. [D. 3966.] 
Fig. 4. Semicytis rugosa^ d’Orb. Middle Chalk — Zone of Micraster 
cortestudinarium : Chatham. A nearly complete zoarium, 
showing the obverse surface ; x 4 dia. Gamble Coll. 
[D. 3967.] 
Fig. 5. Homceosolen fenestratus^ d’Orb. Middle Chalk — Zone of 
Micraster cortestudinarium : Chatham. Obverse face of 
the base of a zoarium with gonoecium ; x 15 dia. Gamble 
Coll. [D. 4365.] 
Fig. 6. Homceosolen fenestratus^ d’Orb. Middle Chalk — Zone of 
Micraster cortestudinarium : Chatham. Obverse face of 
a fragment with long pinnules ; x 12 dia. Gamble Coll. 
[D. 4365.] 
Fig. 7. Homceosolen ramulosus, Lonsd. Middle Chalk — Zone of 
Micraster cortestudinarium : Chatham. -Part of a branch 
showing the whole of a pinnule and a gonoecium ; x 10 dia. 
Gamble Coll. [D. 407.] 
Fig. 8. Homceosolen disparilis (d’Orb.). Upper Chalk : Gravesend. 
Fig. 8g, the whole zoarium, nat. size ; Fig. 86, obverse face 
of one branch, x 6 dia. ; Fig. 8c, the reverse face of 
a branch, x 6 dia. Harford Coll. ' [D. 7281.] 
Fig. 9. Desmepora hlacJcmorei, Greg. Upper Chalk — Zone of Actino- 
camax qu-adratus : East Harnham. Fig. 9a, part of the 
obverse surface, x 6 dia. ; Fig. 96, part of the side of 
a branch, showing the edge of the pinnules and the groups 
of apertures, x 6 dia. Gamble Coll. [D. 4328.] 
