124 



Opheodesoma clavki n. sp. 



Synapta glabra. Thé el. 1885. The Challenger Holothurioidea II, pag. 20. 

 Opheodesoma glabra. Clark. 1924. The Synaptinae, pag. 465 Pl. II 

 fig. 4—6. 



St. Crux Island, Zamboanga. 24.11.1914. The shore. 1 specimen. 



The specimen at hand is but a very young one and does for 

 that reason not measure more than 6 cm in length. The colour 

 is pale green with large white spots, due to heaps of miliary 

 granules. It has 15 tentacles each with 9 — 11 pairs of digits, 

 united by a web. On the oral disk there are eye-spots. The 

 cartilaginous ring (Fig. 4. 4) is rather well developed and the radiais 

 are perforated for the nerves. There are 15 polian vesicles and 

 numerous madreporic canals. The gonads are not developed. The 

 intestine has a loop and on the mesenteries there are small cup- 

 shaped ciliated funnels (Fig. 5. 10). 



The anchors (Fig. 5. 17) measure ca. 180 ft in length by ca. 

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

 are minute knobs. The anchor-plates (Fig. 5. 2) measure 150 — 

 200 ii in length and 140 — 180 [i in width. Their shape is very 

 constant and they have large knobs on the exterior surface. The 

 miliary granules are rosettes (Fig. 5. 9). The figure shows some 

 developmental stages of the rosettes, from which it appears that the 

 rosettes which are so characteristic for the two genera Opheodesoma 

 and Euapta, are but further complicated stages of the rosettes found 

 in Synapta and Synaptala. 



In both the oral disk and the tentacles there are curved rods 

 (Fig. 5. 11-12). These have often branched ends, but they are not 

 swollen and dented as in spectabilis and glabra. 



This species is the most closely related to glabra, with which 

 species it has been confounded, but it differs distinctly from it in 

 the shape of the anchors and plates and in having rods in the 

 tentacles. Probably also the wanting or at any rate very incom- 

 pletely developed cartilaginous ring will prove to be a valid character 

 for separating the two species. 



The three species described above, spectabilis, glabra and clarki, 

 differ distinctly from the other species of the genus. They have all 

 of them a distinct web between the digits, and the shape of the 



