OPHIURANS OF THE PHILIPPINE AND ADJACENT WATERS. 95 



though with some irregularity; they are always lacking beyond the 

 eighth segment. 



Thus the tentacle scales may be completely lacking in certain 

 specimens, and in others may be present in a more or less regular 

 way on a certain number of segments, especially at the base of the 

 arms; a specific difference therefore can not be based on this char- 

 acter, and as all the other characters conform to those which I de- 

 scribed in 1904 in 0. assimilis, I believe it necessary to assign the 

 Albatross specimens to the same species. 



As for the distinction which I have believed it possible to estab- 

 lish between O. assimilis and 0. coriacea Lyman from the Atlantic, 

 I believe that it should be maintained. The Atlantic species has the 

 mouth shields smaller, without the distal lobe which I find con- 

 stantly present in O. assimilis, the upper and under arm plates have 

 a different shape, and, especially, the under arm plates do not show 

 that median notch on their distal border which seems to me con- 

 stantly to occur in O. assimilis. 



Ophiacantha bartletti Lyman and O. paucispma Liitken and Mor- 

 tensen should also be assigned to the genus Ophiotoma. These two 

 species have spines on the two surfaces of the disk, and 0. paucis- 

 pina possesses a very small tentacle scale. 



Very recently H. L. Clark has united O. coriacea Lyman and 

 O. bartletti ('15, p. 217). But I notice that the form of the under 

 arm plates and of the mouth shields as described and figured by 

 Lyman is very different in the two species. I am therefore much 

 puzzled by the synonymy given by H. L. Clark, who, I assume, has 

 been able to examine Lyman's types. The figures and the descrip- 

 tions of that author certainly lead to the conclusion that different 

 forms are concerned; the armature of the disk and the shape of the 

 mouth shields and of the under arm plates do not agree at all. Are 

 there intermediate forms which justify the synonymy indicated by 

 H.L.Clark? 



OPHIOMEDEA DISCREPANS, new species. 



Plate 26, figs. 1-4. 



Locality. — Albatross station 5359; Jolo Sea (lat. 8° 12' 45" N., 

 long. 120° 37' 15" E.) ; 4,161 meters (2,275 fathoms) ; January 9, 

 1909. 



One specimen (Cat. No. 41196, U.S.N.M.). 



Description. — The specimen is unfortunately not in a good state 

 of preservation, and the dorsal surface of the disk is rather badly 

 damaged ; furthermore, the disk has undergone a compression which 

 has deformed it and elongated it in one diameter. The arms are 

 almost complete, except for one which is broken off at the junction 



