A TAXONOMIC STUDY ON PYROSOMA — METCALF AND HOPKINS. 219 



D. 5378, Mompog Island; Mar. 4, 1909; 395 fathoms; one 

 specimen. 



D. 5458, Legaski Light, east coast of Luzon; June 7, 1909; 200 

 fathoms; surface temperature 85° F.; one specimen. 



D. 5498, Bantigui Island, between Leyte and Mindanao; Aug. 3, 

 1909; 960 fathoms; surface temperature 82° F.; one specimen, dried 

 out. 



D. 5514, Camp Overton Light, vicinity northern Mindanao; Aug. 8, 

 1909; 697 fathoms; surface temperature, 83° F.; one specimen, Cat. 

 No. 6489 U.S.N.M. 



D. 5543, Tagolo Light, vicinity northern Mindanao; Aug. 20, 

 1909; 162 fathoms; surface temperature 84° F.; one specimen, Cat. 

 No. 6424, U.S.N.M. 



D. 5607, Binang Unang Island; Gulf of Tomini, Celebes; Nov. 18, 

 1909; 761 fathoms; surface temperature 83° F.; one specimen, Cat. 

 No. 6512 U.S.N.M. 



D. 5214, East of Masbate Island, Philippine Islands; April 21, 

 1908; surface; surface temperature, 81-82° F.; surface density 

 1.02475; two specimens, Cat. No. 6618, U.S.N.M. These specimens 

 we have not had for study. 



D. 5518, northern Mindanao and vicinity, Philippine Islands; 

 Aug. 9, 1909; surface; surface temperature, 85° F.; one specimen, 

 Cat. No. 6617, U.S.N.M. This specimen we have not had for study. 



Three specimens Cat. No. 6499, U.S.N.M. were also obtained at 

 Albatross station D. 3388, latitude 7° 06' N.; longitude 79° 48' W. off 

 the Pacific coast of Panama; March 9, 1891; 1,168 fathoms; surface 

 temperature 73° F. 



Characteristic specimens of this species are found in the United 

 States National Museum Collections, Cat. Nos. 6422, 6423, and 6424. 



PYROSOMA SPINOSUM (Herdman, 1888). 



Plates 19, 20, and fig. 11, plate 21. 



This species was the first of its subgenus to be discovered. Its 

 unique character seems to have been overlooked to some extent until 

 later studies showed that it was organized upon a somewhat distinct 

 plan. In fact, it has been proposed by some writers to place this 

 species and P. agassizi together in a different genus from other Pyro- 

 somas. The studies which have previously been made of this species 

 were conducted chiefly upon Atlantic specimens, though Indian 

 Ocean specimens have also been studied. We have two specimens 

 from the Pacific, and one from the Atlantic Ocean, and in these we 

 find a few new points of interest. 



The colony. It is extremely difficult to secure material of this 

 species suitable for describing the colony-form. Our specimens, like 

 most of the others known, are fragmentary, in consequence of which 



