OPHIUKANS OF THE PHILIPPINE AND ADJACENT WATERS. 13 



be placed in the genus Homalophiura, as H. L. Clark has done; 

 O. undata is given by Matsumoto both in the genus Amphiophiura 

 (p. 78) and in the genus Ophiura (p. 81). I surmise that this latter 

 is a typographical error and that he intended to write (p. 81) O. 

 undulata. 



However, everything considered, this first attempt at a reclassi- 

 fication of the species of the old genus Ophiura is of the greatest 

 interest and marks a very considerable progress. In spite of a certain 

 vagueness which persists in regard to the limits of the genera 

 Amphiophiura and Stegophiura, the genera proposed by Matsumoto 

 are worthy of adoption, and I shall follow his nomenclature in the 

 succeeding pages. 



In his memoir of 19 IT Matsumoto has redefined the characters of 

 the genera established by him in 1915. He accepts H. L. Clark's 

 genus Homalophiura, but he maintains as distinct both 0. inflata 

 and 0. nana. He cites O. undulata (not undata) among the species 

 of the genus Ophiura, in the restricted sense (p. 268). He no longer 

 retains Ophionotus hexactis in the genus Ophiura, and he now 

 agrees with me that this species should be replaced in the genus 

 Ophionotus (p. 235, note). 



A very detailed study of the species assigned to the old genus 

 Ophioconis had led Matsumoto to propose a complete rearrangement 

 of them in 1915. 



The necessity for a revision of this genus, not only to determine 

 the interrelationships of the species commonly assigned to it but 

 also to establish its position in the classification of the ophiurans, 

 had already been suggested by H. L. Clark in 1911 when he was 

 describing his new species from Japan and the Bering Sea ('11, 

 p. 28). When I began in 1914 the preparation of this memoir, I had 

 myself been confronted with this problem, and I was led to establish 

 in the old genus Ophioconis three distinct groups in such a way as to 

 separate from O. forbesi (the type of the genus), on the one hand, 

 O. cincta, O. cupida, O. grandisquama, and O. permixta, which 

 form a very homogeneous group, and, on the other hand, O. miliaria 

 and O. pulver-ulenta. At the same time I proposed to remove from the 

 genus Ophioconis, O. brevispina Ludwig, of which the teeth do not 

 have at all the form characteristic of those of O. forbesi, as well as 

 O. indica, which I proposed, provisionally at least, to place near the 

 genus Pectinura, taken in the sense in which it is understood by 

 H. L. Clark. 



Matsumoto's memoir, dated 1915, reached me in 1916, long before 

 the work which appears to-day was printed, and it is Matsumoto, 

 therefore, who deserves all the credit of having revised the old genus 



