1134 
DE. J. S. BOWEEBANK ON THE ANATOMY 
Explanation of the Plates. 
PLATE LXXII. 
Fig. 1. Grantia. A longitudinal section of a portion of one side of a specimen of 
Grantia ciliata, exhibiting the structure and mode of disposition of the inter- 
stitial cells, X 108 linear : page 1093 : see also Part II. Plate XXXIII. fig. 1, 
for interstitial cells. 
Fig. 2. Leucosolenia hotryoides. Two branches exhibiting the simple fistulose structure 
of the sponge, x50 linear: page 1094. 
Fig. 3. Leuconia nivea. A longitudinal section of one of the mammiform portions, 
exhibiting one of the great cloacal cavities of the sponge and its internal 
defensive spicula, x50 linear: page 1094. 3 «, figure of a sponge, natural 
size. 
Fig. 4. Leucogypsia Gossei. A section at right angles to the surface, exhibiting the 
mass of irregular interstitial structure, x50 linear: page 1095. 
Fig. 5. Geodia Barretti. A section at right angles to the surface, exhibiting the radial 
disposition of the fasciculi of the skeleton, and a portion of the dermal crust 
of the sponge, x50 linear: page 1098. 
Fig. 6. Pachymatisma Johnstonia. A section at right angles to the surface, exhibiting 
the irregularity of the interstitial structures directly beneath the dermal crust, 
x50 linear: page 1101. 
PLATE LXXIII. 
Fig. 1. Ecionemia acervus, Bowerbank, MS. A section at right angles to the surface, 
exhibiting the radial fasciculi of the peripheral system, with the ternate apices 
of the spicula directly beneath the dermal membrane, X 50 linear : page 1101. 
Fig. 2. Polymastia rohusta, Bowerbank, MS. A view of a small portion of the side of 
one of the large cloacae, exhibiting the structure and mode of disposition of 
the longitudinal skeleton-fasciculi, X 25 linear: page 1104. 
Fig. 3. Halyphysema Tumanowiczii^ Bowerbank, MS. A complete sponge, based on the 
stem of a Zoophyte, exhibiting the irregular longitudinal disposition of the 
skeleton-spicula, X 175 linear: page 1105. 
Fig. 4. Ciocalypta. Kepresenting a longitudinal section through the central axis of one 
of the elongate cloacal portions of the sponge, exhibiting the central column 
with the small cylindrical pedicels or short fasciculi of closely packed spicula, 
each terminating at the inner surface of the dermis of the sponge, natural 
size: page 1105. 
Fig. 5. A section of the specimen represented by fig. 4, at about the middle of the 
