A MONOGRAPH OF THE EXISTING CRINOIDS 327 



15 segments, which become about as long as broad on the eighth. The second-eighth 

 segments are rather strongly carinate. P 6 is similar but more slender, 6 mm. long, 

 with only the second-sixth segments carinate. The following pinnules gradually 

 lose the basal carination, become more slender, and increase in length, reaching 8 mm. 

 distally. 



The color in alcohol is brownish purple. 



Notes. — The preceding description was drawn up from the type specimen from 

 Bagamoyo. The other four specimens from Bagamoyo are very young, with the arms 

 about 20 mm. long and the cirri about 6 mm. in length. Two have 11 and two have 

 10 arms. 



A specimen from Zanzibar has the cirri XVI, 25-27. It is smaller than the type 

 specimen from Bagamoyo but is otherwise similar to it. 



A specimen from Waxin has 23 arms 120 mm. long. The IIBr series are 4(3+4), 

 and the IIIBr series are 2. The cirri are XX, 27 ; long sharp dorsal spines are developed 

 from the tenth segment onward. When this specimen is compared directly with a 

 specimen of H. savignii the cirri are seen to be more spiny, the spines first appearing 

 nearer the base, and the proximal pinnules are seen to be larger. 



Of the seven specimens from Kurrachi in the British Museum, one has 21, two 

 have 20, one has 19, two have 18, and one has 17 aims. The largest has the arms 

 130 mm. long and the cirri 25 mm. in length. The specimen with 21 arms has three 

 IIBr 2 series ; two of these are on the same postradial series, one being followed by a 

 single internal IIIBr 2 series. One of the specimens with 18 arms has a single IIIBr 2 

 series. In the remaining specimens the IIBr series are invariably 4(3+4). 



The specimen from Kurrachi collected by the Investigator is medium sized ; there 

 are 26 cirrus segments of which the distal bear strong dorsal spines. 



In the specimen from Kurrachi in the National Museum the cirri are XXIII, 

 28-30, about 20 mm. long. Dorsal spines are present from the tenth to thirteenth 

 segment onward; they are rather smaller than usual. There are about 18 arms. 



In one of the specimens from the Straits of Ormuz the centrodorsal is thin- 

 discoidal with a broad flat finely roughened dorsal pole, the edge of which is abruptly 

 elevated into a smooth rounded arch at the base of each cirrus. The cirrus sockets 

 are arranged in two closely crowded alternating rows. 



The cirri are XX, 28-34, from 20 to 25 mm. long, and rather slender. The longest 

 proximal cirrus segments, the tenth-eleventh or -thirteenth, are from slightly longer 

 than broad to slightly broader than long, and the distal segments are about half again 

 as broad as long. Dorsal spines begin from the twelfth to the fifteenth segment. They 

 are high and conspicuous; the first is slightly smaller than the second, which is as 

 large as those following. 



The nine IIBr series present are all 4(3+4). The division series are broad, 

 moderately rounded dorsally, in lateral contact with sharply flattened sides, which 

 are produced into a narrow coarsely and irregularly tubercular or rugose border which 

 is abruptly distinct from the dorsal surface. 



There are 19 arms about 110 mm. long. The brachials in the distal half of the 

 arms are oblong and very short. 



P D is 7 mm. long, with 24 segments; these at first are twice as broad as long or 

 even broader, gradually increasing in length and becoming about as long as broad on 



