80 THE VOYAGE OF H.M.S. CHALLENGER. 



(13.) December 15, 1875; Pacific, off Valparaiso; surface; lat. 33° 12' 0" S., long. 

 76° 29' 0" W. ; surf. tern]). 62°"5 ; several specimens of the solitary form (mounted on 

 microscope slides). 



(14.) February 12, 1876 ; Station 319, South Atlantic; near the surface; lat. 41° 

 54' 0" S., long. 54° 48' 0" W. ; surf. temp. 59°'5 ; seventy specimens of the solitary form 

 (large and small), also about twenty very young solitary forms about 4 mm. in length ; 

 one thousand to two thousand specimens of the aggregated form (average size 6 mm.), 

 also several mounted on microscoi^e slides, and some of both forms stained in carmine 

 and preserved in glycerine. 



(15.) February 28, 1876 ; Station 323, South Atlantic; lat. 35° 39' 0" S., long. 50° 

 47' 0" W. ; surf. temp. 73°'5 ; several specimens of the aggregated form. 



(16.) February 29, 1876; Station 324, South Atlantic; near the surface; lat. 36° 

 9' 0" S., long. 48° 22' 0" W. ; surf. temp. 7l°'5 ; eight specimens of the solitary form 

 (of fair size), and nearly fifty specimens of the aggregated form (some small). 



(17.) March 1, 1876 ; South Atlantic; near the surface ; lat. 36° 1' 0" S., long. 47° 

 35' 0" AV. ; surf. temp. 72° ; one specimen of the solitary form, and ten specimens of 

 the aggregated form (various sizes). 



(18.) March 3-5, 1876 ; South Atlantic; lat. 37° 0' 0"— 37° 32' 0" S., long. 44° 23' 

 0"— 42° 0' 0"W. ; surf temp. 68° -2— 70° "5 ; one hundred and fifty specimens of the 

 solitary form (about 1 cm. in length), and about one hundred specimens of the aggre- 

 gated form (about 6 mm. in length). 



(19.) March 14, 1876 ; Station, 334, South Atlantic ; lat. 35° 45' 0" S., long. 18° 31' 

 0" AV. ; surf. temp. 68°"5 ; three specimens of the aggregated form (stained and pre- 

 served in glycerine). 



(20.) April 6, 1876; Station 346, Tropical Atlantic; surface; lat. 2° 42' 0" S., 

 long. 14° 41' 0" AV^. ; surf. temp. 82°"7 ; seven specimens of the solitary form. 



(21.) April 11, 1876 ; Station 350, North Atlantic ; lat. 7° 33' 0" N., long. 15° 16' 

 0" AV. ; surf. temp. 84° ; four small specimens of the solitary form. 



(22.) April 13, 1876 ; Station 352, North Atlantic, off the AA^est coast of Africa ; lat. 

 10° 55' 0" N., long. 17° 46' 0" AV. ; surf. temp. IT'l ; one specimen of the solitary form. 



(23.) May 3, 1876; Station 353, North Atlantic; tow-net down to 80 fathoms; 

 lat. 26° 21' 0" N., long. 33° 37' 0" AV. ; surf. temp. 70°-7 ; two specimens of the solitary 

 form (one very small), and three specimens of the aggregated form (poor specimens). 



(24.) Collected during the second cruise of H.M.S. " Porcupine " in the summer of 

 1869 ; Station No. 33, off the South Coast of Ireland, surface ; several specimens of 

 both the solitary and the aggregated forms. 



The Challenger collection of this species shows a considerable amount of variation 

 both in size and shape. Taking the solitary form first, we find specimens ranging from 

 5 mm. to nearly 15 mm. in length of body, exclusive of the posterior prolongations or 

 spines, collected on the same occasion (April 2, 1874, off the Australian coast). The 



