OPHIURANS OF THE PHILIPPINE AND ADJACENT WATERS. 325 



the description published by Lyman (pi. 73, figs. 1, 4). I also give 

 (fig. 3) a photograph of another specimen from station 5109 in 

 which the two dorsal spines, instead of being the longest, are shorter 

 than the lateral spines, but they are rather strongly swollen, recall- 

 ing the form which is often observed in O. erinaceus, for example ; 

 the lateral spines have the usual length. In another individual 

 shown in figure 2 the thickening of the two dorsal spines is still 

 more marked; these spines are very short, their length scarcely 

 equaling two segments, and they are much swollen in their central 

 region. The lateral spines are not thickened, but they are shorter 

 than usual, and their length scarcely exceeds that of the two dorsal 

 spines. This specimen came from Mauritius. It is part of a small 

 but very interesting series which I have in which I find all possible 

 intermediates between very slender and much elongated dorsal spines, 

 such as those most often met with, and spines which are short, thick- 

 set, and very strongly swollen. 



Similar variations have often been noticed in O. scolopendrina and 

 in O. erinaceus, but I do not know that they have ever before been 

 described in O. Imeolata. 



The remarks given by Miiller and Troschel on the subject of the 

 arm spines of 0. Imeolata are not very clear. These authors say, 

 speaking of 0. pica, that the spines are slender, twice as long as the 

 upper arm plates, and a little longer than the width of the arms ; and 

 of those of O. lineolata that they are all almost of the same length, 

 this length equalling the width of the arms, and a little thicker at the 

 base of the arms. According to Lyman, who has seen Miiller and 

 Troschel's original specimens, these spines are more elongated than 

 these authors describe; in a specimen of O. pica in which the diameter 

 of the disk is 15 mm. the first dorsal spine is 3.2 mm. long; in 0. 

 lineolata the dorsal spine and the lateral spines are longer than the 

 others. 



Ophiocoma lineolata, from which it is not necessary to separate 

 0. pica Miiller and Troschel and 0. sannio Lyman, is widely distrib- 

 uted throughout the whole Indo-Pacific region. It is frequently asso- 

 ciated with O. scolopendrina and with 0. erinaceus, but it is usually 

 less abundant than the two last. 



OPHIOCOMA SCOLOPENDRINA (Lamarck). 



Plate 73, fig. 5; plate 74, figs. 1-7. 



See for bibliography: 

 Ophiocoma scolopendrina Kcehifr ('05), p. 60: ('05a). p. 184; ('07), p. 



326; ('07b), p. 246.— H. L. Clark ('08), p. 297.— Macintosh ('11), p. 



160.— H. L. Clark ('15), p. 293. 

 Ophiocoma scolopendrina typical Matsxjmoto ('17), p. 346. 



Localities. — Port Binang, Subig Bay; January 9, 1908. 

 One specimen (Cat. No. E. 218, U.S.N.M.). 



