142 BULLETIN 82, UNITED STATES NATIONAL MUSEUM 



of 7-18 (usually 9-12) segments. P c resembles P 3 and is shorter than P b . In one 

 case it is 4 mm. long with 12 segments. P 4 is commonly nearly or even quite as 

 short and small as P 6 , these being the smallest pinnules on the arm. When P 3 is very 

 short, P 4 may be of the same length, though it is usually shorter, and often much 

 shorter. It is from 2 to 5 (most commonly between 2.5 and 3) mm. in length, and is 

 composed of 9-15 (usually 10-12) segments. In contrast to the pinnules immediately 

 preceding, it is always smooth. 



The distal pinnules are from 3.5 to 8 (usually about 5) mm. long, and are com- 

 posed of 14-22 (most commonly about 18) segments of which the first two are short 

 and broader than those succeeding, the second with a more or less marked distal keel, 

 the third is about as long as broad, and those following are long and slender, from 

 two to three times as long as broad. The terminal segment is provided with micro- 

 scopic dorsal hooks. 



The disk is from 3 to 10 (most commonly from 4 to 8) mm. in diameter, and is 

 naked and smooth and very deeply incised. Sacculi are very abundant on the arms 

 and pinnules. 



Notes. One of the specimens from Tokyo Bay in 15-22 meters, with 20 arms, is 

 large and richly colored. 



The specimen from Tokyo Bay in 24 meters in the Museum of Comparative 

 Zoology has 20 arms. 



The specimen from the Uraga Channel in 36-55 meters in the U. S. National 

 Museum has 20 arms. According to Dr. Hubert Lyman Clark the one in the Museum 

 of Comparative Zoology is about 90 mm. in diameter that is, has an arm length of 

 about 45 mm. The color of the latter in alcohol is pale purple, the arms banded with 

 whitish. 



The example from the Uraga Channel in 46 meters has 13 arms. 



The specimens from the Uraga Channel in 146 meters are both small. One has 

 15 and the other has 20 arms. 



The three specimens from the Uraga Channel in 150 meters have 18, 19, and 20 

 arms about 80 mm. long. 



The example from the entrance to the Uraga Channel in 135 meters has 18 arms 

 about 60 mm. long. 



The specimen from Albatross station 5094 has 17 arms and is large and richly 

 colored. 



The six specimens from Albatross station 5095 are all large and richly colored, 

 and all have 20 arms, which in one are 60 mm. long. 



The specimen from Albatross station 5071 has 20 arms and is large and richly 

 colored. 



The example from Albatross station 3701 has 14 arms. 



From Albatross station 3707 there are 5 specimens with 17 arms, 2 with 18 arms, 

 5 with 19 arms, 37 with 20 arms, 7 with 21 arms, and 3 with 22 arms 59 in all. The 

 arms are up to 65 mm. in length. 



One of the specimen from Albatross station 3708 has 20 arms. 



The example from Albatross station 3713 has 13 arms. 



The two specimens from Albatross station 3715 both have 20 arms. 



