THE DIGESTIVE ORGANS OF THE ALUYONARIA. 
327 
The Digestive Organs of the Alcyonaria and their 
Relation to the Mesoglceal Cell Plexus. 
By 
Edith M. Pratt, D.Sc.(Vict.). 
(With Plates 20—22.) 
ConrtTeENTS. 
InrTRopvcTION, with observations on the anatomy and food of Alcy- 
onium, Sarcophytum, Lobophytum, and Sclerophytum 
THE Zoorps : 
Distinction eee Fonids, pape ese ial Sauaienaee 
Tentacles; Pinnules; Nematocysts. 
THE Foop oF THE ALCYONARIA : 
Statement of our knowledge of the food of sMteronanias shaydetipat 
tion of the nature of the food in tropical and British members 
of the family belonging to the genera mentioned inthe Intro- 
duction. 
FEEDING EXPERIMENTS ON ALCYONIUM DIGITATUM 
Histotocy oF tHE Movuts Disc : 
Tue Stomopzum. Its histology and digestive peterien 
THE SIPHONOGLYPH . 
THE MESENTERIES - : 
Of Autozooids. Of Siphonozooids. 
Tue MESENTERIAL FILAMENTs and their origin 
The Dorsal Mesenterial Filaments. The Ventral Meena 
Filaments. Their histology in starved and well-fed zooids. 
Their digestive function. Intra-cellular digestion. Discus- 
sion of evidence in favour or otherwise of the occurrence 
of an intercellular digestion in other groups. The presence 
of an intercellular digestion in Aleyonaria demonstrated by 
feeding experiments on Alcyonium. Reduction in size of 
these filaments in tropical forms associated with the increased 
abundance of zoochlorelle. Probable symbiosis. 
VoL. 49, pART 2,—NEW SERIES. 23 
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