A MONOGRAPH OF THE EXISTING CRINOIDS 277 



process of the type seen in H. crenulata, which is repeated, less developed, on the oppo- 

 site side of the pinnule. In the distal portion of the pinnule the entire distal end of 

 the segments is somewhat overlapping. P 4 and the following pinnules are 4 mm. long 

 with 12 segments increasing in length to the third, which is about as long as broad, 

 then increasing distally to about three times as long as broad, the three or four ter- 

 minal being shorter again. The distal pinnules are 6 mm. long. 



The color in alcohol is flesh color, clouded with violet. 



Notes. — I am not wholly convinced that the specimen from the Maldive Islands 

 should be referred to this species. It has only 10 arms. There are 23-25 cirrus 

 segments, which from the tenth onward bear small dorsal spines. The segments of 

 the proximal pinnules have slightly projecting and spinous distal ends. It is possible 

 that the specimens from the Aru Islands described by Reichensperger under the 

 name of Amphimetra variipinna (see page 281) should be referred to this form, as well 

 as the specimen he described under the name of Craspedometra anceps (C. aruensis, 

 n.sp.?). 



Remarks. — This species appears to be most closely related to H. crenulata, but it 

 differs in its cirri, which are more slender, especially distally, with rudimentary dorsal 

 spines and longer terminal segments, the total number of the segments being less; 

 in its lower pinnules, which are not nearly so much enlarged and of which the com- 

 ponent segments have less produced distal edges; and in its general build, which is 

 considerably more slender. The general ruggedness so very characteristic of H. 

 crenulata is quite absent in this species, and the overlapping of the brachials is much 

 less marked. 



Localities. — Singapore ; Svend Gad [A. H. Clark, 1908, 1909 1918] (1, C. M.). 



Fadiffolu, Maldive archipelago; J. Stanley Gardiner [A. H. Clark, 1912, 1913] 

 (1,B. M.). 



History. — This species was described in 1908 under the name of Himerometra 

 producta from a single specimen from Singapore. On the establishment of the new 

 genus Amphimetra in 1909, producta was assigned to it. Later in 1909 the features 

 distinguishing it from H. crenulata were given in detail. In 1912 it was compared with 

 H. propinqua (see below), and hi another paper with the type specimen of H. variipinna 

 (see p. 278). In 1913 it was recorded, as Amphimetra producta, from the Maldive 

 Islands on the basis of a specimen in the British Museum that had been labeled 

 tAntedon laevissima by Prof. F. Jeffrey Bell. In the report on the unstalked crinoids 

 of the Siboga expedition published in 1918 producta was transferred to the genus 

 Heterometra. 



HETEROMETBA PROPINQUA (A. H. Clark) 



Plate 25, Figures 97-100 



Amphimelra propinqua A. H. Clark, Ann. Mag. Nat. Hist., ser. 8, vol. 10, 1912, p. 31 (description; 

 Siboga station 318) . 



Heterometra propinqua A. H. Clark, Unstalked crinoids of the Siboga-TZxped., 1918, p. vm (dis- 

 cover}' by the Siboga and its significance), p. 76 (in key; range), p. 80 (detailed description; 

 stations, 318, 320), p. 276 (listed), pi. 18, figs. 33, 34.— GislSn, Kungl. Fysiogr. Sallks. Handl., 

 new ser., vol. 45, No. 11, 1934, p. 22. 



Diagnostic features. — This species very closely resembles//, producta, but the cirri 

 are slender and tapering with all the component segments approximately subequal in 



