. An account of the alcyonarians collected by the Royal Indian marine survey ship Investigator in the Indian Ocean. Alcyonaria. Fig. 20. D. costato- rubra. Fig. 20a. D. costato- rubra.—b, from stem cortex ; c, from stem canal walls. the length averaging 0-48 mm. and the breadth 0-6 mm. They are placed on the stalk at an obtuse angle, which often approaches very nearly to a right angle. They are roundish oval in shape, the long axis being parallel to the stalk. The younger polyps are much smaller on an average, measuring 0 27 mm. in length and 03 mm. in breadth. The spicules are arranged in eig
. An account of the alcyonarians collected by the Royal Indian marine survey ship Investigator in the Indian Ocean. Alcyonaria. Fig. 20. D. costato- rubra. Fig. 20a. D. costato- rubra.—b, from stem cortex ; c, from stem canal walls. the length averaging 0-48 mm. and the breadth 0-6 mm. They are placed on the stalk at an obtuse angle, which often approaches very nearly to a right angle. They are roundish oval in shape, the long axis being parallel to the stalk. The younger polyps are much smaller on an average, measuring 0 27 mm. in length and 03 mm. in breadth. The spicules are arranged in eight double rows, in each of which there are four to five pairs of converging spicules. It is the exception for any of these to project beyond the polyp-head, but in one or two cases the uppermost project a very little. The spicules of the lateral rows are occasionally a little larger, but seldom project at all. The polyp- spicules are somewhat flattened spindles, straight or slightly curved, with simple spines ; they often measure about 0'36 mm. in length, but are usually smaller. The Stutzbundel is well developed, consisting of two to three large, and a number of smaller spicules. One of the larger projects considerably, and very often a second also projects. In younger polyps the Stiitzbiindel is not so pronounced but still is (juite distinct, while in the youngest polyps its presence can be detected only from the fact that spicules are more numerous on the dorsal side of the short polyp-stalk. Cortical spicules : (a) Those of the stem are slender spindles, straight or curved, 06 to i^ mm. long, 003 to 015 mm. thick. They form an irregular mesh-work, the smaller spicules lying in the larger meshes or running from one mesh to another. This arrangement is marked out by the presence of spicules either pink in colour or with a pinkish core. (b) Those of the stalk are large spindles straight or curved, clubs, three-. Please note that these images are extracted from scanned page i
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Keywords: ., bookauthorthomsonjarthurjohnart, bookcentury1900, bookdecade1900
