131 



the skin is removed it is possible to see the well developed eyes, 

 which are united with the oral ring-nerve by distinct nerves, one 

 for each eye. The cartilaginous ring is large, and the pure white 

 calcareous ring is stouter than in any other species of the Synaptinae 

 here examined. The calcareous ring (Fig. 4. 1) is of the same 

 length as in grisea, but the anterior processes are shorter, and the 

 thickness of the ring is greater than its length. The radial processes 

 are perforated for the nerves and all the processes are united by 

 a low web. There are numerous polian vesicles and madreporic 

 canals. The gonads are branched. The intestine has a loop and 

 on the base of the mesenteries there are ciliated funnels of the 

 usual shape and size. 



The anchors (Fig. 7.5) measure ca. 330 ^ in length by ca. 

 220 ju in width. The stock is branched and on the vertex there 

 are minute knobs. The anchor-plates (Fig. 6. 17) measure ca. 260 

 fi in length by ca. 200 /ti in width and have on the exterior surface 

 the common two rows of large knobs around the holes. The shape 

 of the articular end is very variable (Fig. 6. 14-17). The miliary 

 granules are rosettes, found all over the skin and in the tentacles. 

 In the oral disk there are ca. 80 /u long rods with swollen and slightly 

 branched ends (Fig. 7. 10). Rods are not found in the tentacles. 



This species is the most closely related to grisea, as the pure 

 white calcareous ring separates it distinctly from the other species 

 of the genus which are wanting the web between the digits. From 

 grisea it differs especially in the peculiar shape of the calcareous 

 ring. Furthermore the shape of the anchors and plates as well as 

 that of the oral rods show marked differences. 



Opheodesoma lineata n. sp. 



West of Koh Kut. Gulf of Siam. 4.III.1900. Ca. 15 fms. Mud. 1 fragment. 



The fragment at hand measures 30 cm in length, though both 

 the anterior and the posterior end are wanting. The colour (Pl. II 

 Fig. 2-3) is very characteristic of the specimen. The dorsal side of 

 the body is dark olive-green with white or bright yellow spots and 

 stripes and the ventral side is uniformly grey. The intestine has 

 a loop and on the mesenteries there are ciliated funnels of the 

 usual size and shape. 



9« 



