63 



resembling P 4 but very slightly stouter basally and with longer distal segments; tlie following 

 pinnules resemble P. ; the distal pinnules are 4 mm. long with 15 segments of which the distal 

 are nearly or quite three times as long as broad. 



The colour is white with numerous regular purple spots on the division series and arm 

 bases and in band-like areas on the distal part of the arms; the cirri are white, with a band 

 of purple on each segment. 



In this specimen there are eight IIBr 4 (3 + 4) series and one IIBr 2 series; a HIBr 

 2 series is developed internally on one of the IIBr 4 (3 + 4) series. 



A similar specimen has seventeen arms, with five IIBr 4 (3 + 4) series and two IIBr 2 

 series; the cirri are XVII, 18, 9 mm. long. 



The remaining two specimens are small. 



This curious little species has caused considerable trouble. lts general appearance is such 

 that it is very easily confused with Heteromctra bengalcnsis with which, moreover, it agrees in 

 colour, differing entirely from any species of Zygometridae heretofore known. 



All of the records of Hetei'ometra bengalensis from Australia (from Port Curtis and the 

 Holothuria Bank) refer to this form. 



Very recently Dr. Hubert Lyman Clark has redescribed this species (Publication N° 212 

 of the Carnegie Institution of Washington, 191 5, p. 105) under the name of Heterometra 

 delicata, basing his description upon a specimen which he found on the sand flat on the southern 

 side of Friday Island, Torres Straits. 



Catoptometra A. H. Clark. 

 Key to the Species of the Genus Catoptometra. 



a 1 40 — So arms; all the division series 2 (Philippine Island s) magnifica 



a 2 less than 30 arms; IIBr series 4 (3 + 4) 



b 1 11 — 13 arms; cirri short and stout, few or none of the component segments 

 being longer than broad; in life banded broadly with brilliant red and 

 brilliant yellow alternately (Hong Kong to southern Japan). . . mbroflava 

 b~ 20 or more arms; cirri longer and less stout, the longest segments being 

 twice as long as the median diameter; in life usually uniform in colour, 

 yellow, brown or green, rarely red and yellow 



c 1 20 arms; 15 — 16 cirrus segments; ossicles of the division series and 

 first two brachials with prominently everted and produced spinous 

 distal borders; dorsal pole of the centrodorsal papillose or finely 



spinous (southern Japan) fiart/auói 1 ) 



c- 20 — 27 arms; 15 — 19 (usually 17 — 18) cirrus segments; ossicles of 

 the division series and arm bases smooth ; dorsal pole of the centro- 

 dorsal smooth; colour usually green, rarely red and yellow (Malay 

 Archipelago and Philippine Island s) ophiiira 



1) Synonym Zygometra hoihteri A. H. Clark. 



