1910.] FROM MERGUI ARCHIPELAGO. 187 



Colochirus inornatus von Marenzeller. 



Colochirus inomatus von Marenzeller, 1881 (10); Lampert, 

 1885(13); Theel, 1886 (15). 



Six specimens. Locality not given, 

 mm. 



Length 65 



Breadth 14 



These specimens agree with Theel's description. They have 

 the form which is typical of the genus Colochirus, i. e. a quad- 

 rangular body which becomes pentagonal at either end. The 

 pedicels are confined to the ventral surface and are arranged in 

 three rows. This species differs from many other members of 

 this genus in not having the large tubercles. The colour in 

 spirit is yellowish-white on the trivium and brown on the rest 

 of the body. The pedicels are yellowish-white. There are ten 

 tentacles, the two ventral ones being smaller than the rest. The 

 tentacles are yellow. 



The deposits are typical. 



Length of perforated plates 67 n ; width 48 yu. 



Length of large scales 300^. 



Length of buttons 74 fx. 

 General distribution. Japan, ' Challenger,' 11° 6' N., 123° 9' E. 



Colochirus cucumis Semper. 



Colochirus cucumis Semper, 1868 (7); Lampert, 1885 (13); 

 Theel, 1886 (15); Sluiter, 1887 (18); Sluiter, 1901 (20). 



Eleven specimens from Station IX. Between Bentinck Is. and 

 Courts Is. 



mm. mm. mm. mm. mm. mm. mm. mm. mm. mm. mm. 



Length 19 24 22 22 31 32 40 47 47 48 60 



Breadth 6 7 7 8 9 11 14 13 18 19 22 



One specimen from Station XXIV. Cat Is. 



Length 62 mm. ; breadth 24 mm. 

 One specimen from Station XXXIII. " Christmas Is. Group." 



Length 25 mm. ; breadth 9 mm. 

 One specimen from Station XVII. "West of Sir John Mal- 

 colm Is. 



Length 70 mm. ; breadth 16 mm. 

 One specimen from Station XXII. Hastings Harbour. 



Length 17 mm. ; breadth 6 mm. 

 Externally the specimens agree with Theel's description. The 

 posterior end of the body is upturned so that the anus assumes 

 a dorsal position. There are five anal teeth. Contrary to Theel's 

 statement, there appear to be scales around the anus. The body 

 is broad in front and gradually tapers towards the posterior end. 

 There are the well-defined double rows of pedicels on the trivium. 

 The calcareous ring (text-fig. 19) is composed of ten simple pieces 



