28 Coelenterata. 



According to Pratt (*) the Ceylon Alcyoniidse are very similar to those of the 

 Maldives, Sa/rcophytwm, Lobophytum, Sclerophytum and Alcyonium being found 

 in both localities. In Scl. herdmani there are on the wrinkled stalk, some 

 distance below the capitulum, 3 small tubercles bearing zooids on their upper 

 surface. This species is monomorphic, the autozooids being very small and 

 having feebly developed ventral mesenterial filaments, this being correlated, as 

 in several other similar examples, with a great abundance of zoochlorellse in 

 the endodermal tissue and canals. In a specimen of Scl. densum some of the 

 zoochlorellse have lost their cellulose walls, and the nucleus, chromatophore 

 and cytoplasm show signs of division, probably spore formation. Possibly the 

 rounded yellow cells |in the ectoderm and endoderm represent an early stage 

 of sporogenesis. Neruatocysts, in the Alcyoniidse, always occur in batteries 

 and never uniformly distributed in the ectoderm. They attain their greatest 

 size (16-22 ,u long) in Sarc. glaucum, the unbarbed thread is short and broad 

 and lies in 3 or 4 loose irregular turns. In Scl. durum the uematocysts are 

 only 5 long. The discharge of ova in these Alcyoniidie probably extends 

 over a considerably longer period than in the case of those forms found in 

 cooler waters ; male colonies were not found in the collection. Ova were found 

 in the dorsal mesenteries in Scl. gardineri. Siphonozooids and autozooids often 

 communicate by means of short canals, the elongate columnar endoderm cells 

 of which bear long flagella. In the stomodreum of siphonozooids there is an 

 increase in the number of flagellated cells accompanied by a reduction in the 

 number of gland cells, the latter are very scarce in Sarc. and Lob. and entirely 

 absent in Sd. in which the siphonozooids are either minute or absent. In 

 Scl. densum and hirtum the stomodieum of the siphonozooids consists of a 

 short simple tube lined by undifferentiated ectoderm cells, in palmatum and 

 capitals there is no aperture to the exterior, in durum and polydactyhmi the 

 stomodiuum is represented by an aggregation of a few ectoderm cells, while 

 in gardineri and querciforme it is entirely unrepresented. Mesenteries are 

 present only in few cases and are very small. The siphonozooid buds differ 

 from those which are destined to become autozooids by being arrested in their 

 development at a very early stage, which appears to be constant for the species. 

 The author describes Sarc. 5 (3 n.), Lob. 2, Scler. 8 (1 n.), Alcyonium 2 (1 n.). 



According to Pratt (-) in Alcyonium large food bodies are rapidly broken 

 up into small particles, and in some cases (e. g. Crustacea, fish ova) are ap- 

 parently acted on by some digestive ferment in the crelenterou of the zooids 

 before being ingested by the ventral mesenterial filaments. The filaments of 

 hungry zooids are crowded with gland cells containing numerous granules which 

 stain black with iron hsematoxylin ; similar cells also occur in the stomodieum 

 and oral disc. After feeding, these gland cells contain few or no granules. 

 Pounded flesh of whiting and other fish, stained with carmine was ingested, 

 grasped by the mesenterial filaments and rapidly disappeared, at the same 

 time the filaments increased in size and became red in colour. The endoderm 

 cells of the filaments ingest food in an amoeboid manner, when within the cells 

 the food is soon enveloped in food vacuoles and disintegrated. Particles of 

 waste matter were extruded from some of the cells. In tropical Alcyonaria 

 the ventral mesenterial filaments are frequently small. Those of Lobo- 

 phytum resemble those of the British Ale. being only slightly reduced; food 

 material has been observed in the cosleutera of Lob. and zoochlorellce are not 

 numerous. In Sareophytum there is a mesoglceal thickening at the edge of 

 the mesenteries but the filaments are smaller than those of Lob. and have few 

 gland cells, zoochlorellas are moderately numerous. In the tropical species of 



