550 BULLETIN 82, UNITED STATES NATIONAL MUSEUM 



other. On each side of the arm protuberances and depressions alternate so that the 

 surface here has a wrinkled or pleated appearance which is very characteristic of the 

 species. The brachials following are triangular, farther out becoming bluntly wedge- 

 shaped and then again moderately discoidal. The outermost brachials are approxi- 

 mately square. Syzygies occur between bracliials 3+4, again from between brachials 

 15+16 to between brachials 22 + 23, and distally at intervals of 7-9 muscular ar- 

 ticulations. 



Pi is about 9 mm. long. It is moderately thick at the base but becomes very 

 slender and delicate in the distal half. P tt is markedly smaller. The pinnules of the 

 two following pairs are about 12 nun. long. The difference in size between the pinnules 

 of these two pairs is very slight, but P 3 and P are a little longer than P 2 and P„. 

 They are composed of about 25 segments of which some may be a little longer than 

 broad. The length of the pinnules of the three following pairs decreases. The distal 

 pinnules are 7 mm. long. The disk is 15 nun. in diameter and is incised. Sacculi 

 are very abundant on the pinnules. The dorsal skeleton and the disk are uniform 

 dark gray-brown; the centrodorsal, the cirri, and the ends of the arms are lighter 

 chocolate-brown. 



Hartlaub said that this specimen differs from the type specimen of elongata from 

 New Guinea at Leyden in various features, and before he had compared them directly 

 the specific identity of the two seemed to him doubtful. 



The centrodorsal of the specimen from Amboina (in the Gottingen Museum) is 

 quite flat, and there are XX-XXV cirri, while the centrodorsal of the type specimen 

 is "moderately thick convex," and there are XXX cirri. The postradial series of the 

 type specimen are "well separated," while those of the specimen from Amboina are 

 in lateral contact. Carpenter gave the position of the second syzygy in the type 

 specimen as usually from between brachials 9 + 10 to between brachials 18 + 19, 

 while Hartlaub found in the specimen from Amboina that it was not earlier than be- 

 tween bracliials 15 + 16. Carpenter said that in the type specimen P,j and P 6 are 

 "a good deal smaller than that on the right, but larger than the first pair," while 

 Hartlaub found them always smaller than Pi and in no case larger than P a , which 

 sometimes is weaker than P t . Finally, the distal pinnules of the typo specimen are 

 markedly longer than those in the specimen from Amboina. Carpenter said that 

 "they never exceed the length of the third pair," or in other words, that their length 

 occasionally reaches that of the third pair. Hartlaub said that in the specimen from 

 Amboina this is never the case. 



Hartlaub said it seemed to lum that the differences mentioned between the speci- 

 men from Amboina and the type specimen of elongata are not of sufficient importance 

 to justify a separation into two species, especially since the general habitus of the two 

 individuals is quite the same, and more particularly since the uneven and pleated 

 surface of the basal portion of the arms is a characteristic feature of the species. He 

 said that this species (elongata) is in every respect very near flageUata but differs from 

 it in the character just mentioned and also in the very different form of the centro- 

 dorsal ; also the number of arms is much smaller than in flageUata. 



The specimen from Siboga station 250 has 20 arms 115 mm. long, all the IIBr 

 series being present. The cirri are XXIV, 24-25, 18 mm. long; dorsal spines are 

 developed from the tenth or eleventh segments onward. Pi is 4.5 to 6.0 mm. long. 



