80 ART. 2. — H. MATSUMOTO: 



Hirado Strait ; 72 m. (Döderlein). 

 Zanzibar (Dödeelein). 



Astrohoa arctos Matsumoto. 



Astrohoa arctos : Matsumoto, Proc. Acad. Nat. Sei., 1915, p. 57. 

 Two specimens ; off Moroiso, Misaki ; 5-10 fathoms. Four 

 specimens ; off Misaki. 



Diameter of disk 65 mm. 



Distance from the centre of tlie disk to the interbrachial margin. . . 25 mm. 



From the outer end of the oral slit to the I''*- bifurcation 32 mm. 



From the I'''- bifurcation to the 2"'^- 10 mm. 



From the disk margin to the 2"'^- bifurcation 4 mm. 



From the 2°'^- to the S'*^- .... 12 mm.-16 mm 14 mm.-13 mm. 



I I 



From the 3"'- to the 4*'''- 18 mm.-8 mm. ..11 mm.-15 mm. 



I I 



From the 4"^' to the 5*'' .... 10 mm.-18 mm. , 16 mm.-ll mm. 



1 1 



From the 5''' to the 6"'- 17 mm.-9 mm.. .10 mm.-18 mm. 



I I 



From the 6"'- to the 7"'' .... 9 mm.-16 mm 14 mm.-ll mm. 



1 1 



From the 7"'- to the 8*- 15 mm.-8 mm. . . 9 mm.-17 mm. 



I I 



From the 8*''- to the 9*' .... 8 mm.-16 mm 14 mm.-ll mm. 



1 I 



From the 9*- to the 10"^- 16 mm.-8 mm. . . 8 mm.-14 mm. 



I I 



From the 10"'- to the 11*'' ■ , . 8 mm.-16 mm. , 13 mm.-8 mm. 



I I 



From the ll'''- to the 12'''- 15 mm.-6 mm. . . 7 mm.-20 mm. 



I I 



From the 12*''- to the 13"'' . . 6 mm.-17 mm^ 11 mm.-7 mm. 



I I 



From the 13"' to the 14*''- 15 mm.-6 mm. , . 7 mm.-ll mm. 



I I 



From the 14"'' to the 15'''- . . 6 mm.-lO mm 10 mm.-5 mm. 



1 I 



From the 15"'' to the 16*^ 14 mm.-6 mm. . . 5 mm.-9 mm. 



i I 



From the 16*''- to the 17* . . 6 mm.-ll mm 11 mm.-5 mm. 



I I 



From the 17"'- to the 18"'- 14 mm.-5 mm. . . 6 mm.-9 mm. 



I I 



From the 18*''- to the 19"'- . . 4 mm.-12 mm 14 mm.-5 mm. 



I 1 



From the 19*''' to the 20*''' 16 mm.-5 mm. . . 6 mm.-lO mm. 



