284 PKOF. ALLMAX ON NEW GENEUA AND SPECIES OF HTDUOIDA. 



Plate XX. 



Figs. 1-4. Pericladium bidentaium. 



1. A portion of a colony, natural size. 



2. One of the bifurcating branches, magnified. 



3. A portion of a branch near its proximal end, with gonangia, 



still more magnified. 



4. A portion of a branch near its distal end, magnified still further. 



Plate XXI. 



Figs. 1-4. Aglaophenia acanthocarpa. 



1. A colony, natural size. 



2. Portion of a pinna, magnified, lateral view. 



3. Same, front view. 



4. A corbula, magnified. (In order to give the figure greater 



clearness the leaflets of one side are omitted.) 



5-7. Aglaophenia laxa. 



5. A colony, natural size. 



6. Portion of a pinna, magnified, lateral view. 



7. Same, front view. 



Plate XXII. 



Figs. 1, 2. Halicornaria saccaria. 



1. A portion of stem with two pinnre, one carrying a gonaugium, 



magnified, lateral view. 



2. A gonangium, less magnified than in fig. 1, front view. 

 (For Halicornaria saccaria, nat. size, see PI. XV. fig. 4.) 



3, 4. Halicornaria insignis. 



3. Portion of a pinna, magnified, lateral view. 



4. One of its hydrotbecEe, front view. 



(For Halicornaria ioisigoiis, nat. size, see PL XXIII. fig. 1.) 



Fig. 5. Halicornaria hipinnata, portion of stem and pinna, magnified. 

 (For Halicornaria bipinnata, nat. size, see PI. XXIII. fig. 2.) 



Plate XXIH. 



Fig. 1. Halicornaria insignis, nat. size. 



2. Halicornaria bipinnata, nat. size, drawn from a small specimen. 

 (For the magnified details of this plate see Plate XXII. figs. 3, 4, 5.) 



