318 



which is, as said, turned against the Cidarid-spine. They measure 

 ca. 200 fi in length. The hook is rather short (Fig. 68. 4-5) and 

 the inrolled end is usually irregularly branched like that of the hooks 

 in contortus (Fig. 68. 6-7). The spicules from the tentacles (Fig. 

 68. 9) measure ca. 100 /lv, and their ends are distinctly branched. 



Tœniogyrus cidaridis is a rather interesting species which is easily 

 recognized by the shape of the calcareous ring, the hooks and the 

 tentacle-rods. From the two other species, found commensally 

 with Cidarids, keiensis and clavus, it differs distinctly in the shape 

 of the hooks and the tentacle-spicules. 



Tœniogyrus clavus n. sp. 



The Kei Islands. St. 41, 5028' 40" S., 132°28' E. 245 m. Mud. 25.IV.1922. 

 1 specimen. 



St. 46, 5047'20"S., 1320 13' E. 30 o m. Mud. 2.V.1922. 

 4 specimens. 



St. 50, 50 34' S., 1320 25' E. 233 m. Sand. 4. V. 1922. 

 9 1 ) specimens. 



The specimens at hand are very like keiensis and cidaridis, and 

 like these specimens they are confined to Cidarid-spines. They are 

 in alcohol white with yellowish tentacles. The arrangement of the 

 wheel-papillae is quite as in cidaridis, with numerous papillae on 

 the dorsal side, and hooks on the ventral side. There are ten ten- 

 tacles each with 5 pairs of digits. The calcareous ring (Fig. 68. 15) 

 consists of ten pieces, the radiais being characterized by a large, 

 square projection on the anterior margin. There is one polian ve- 

 sicle and a single stone-canal. The madreporite (Fig. 68. 16) is 

 irregularly ring-shaped. The alimentary canal has a large loop, 

 and the gonads are very voluminous and unbranched. The sexes 

 are separate. Ciliated funnels could not be made out. 



The wheels are of the usual shape and measure 35 — 140 ^ in 

 diameter. The sigmoid bodies (Fig. 68. 11-12) measure ca. 175^ 

 in length. The hook is rather large and the inrolled end is not 

 branched (Fig. 68. 13-14). In the tentacles there are rather large 

 and very characteristic spicules (Fig. 68. 10). They measure ca. 

 120 — 150 (J, in length and their ends are unbranched and spiny. 



!) From this locality there are some more specimens, but they are still 

 remaining on the corresponding Cidarids. 



