4i 



shallow or deep depressions, being places where no fusion took place. They can be compared 

 to the depressions on the top we mentioned (p. 40) in 1341 a and 1341 c. I suppose that in the 

 same way the openings on the surface have to be explained in Hymeniacidon angulata a. o. 



As to the curious design we find on the surface of S. areolata (PI. III, üg. 4), we have 

 already demonstrated that this is probably more due to shrinking by drying than a peculiar 

 character. If we compare Spirastrella cunctatrix B. M. 13 with Suberites wilsoni B. M. 15 and 

 Spirastrella areolata B. M. 2, which are all three in the dried state, we have before us an 

 instructive series: in the first chiefly tubercles, in the second irregular lines, in the third mult- 

 angular ridges prevailing. In 5. cunctatrix B. M. 10 we have the tubercles of B. M. 13, the 

 lines of B.M. 15 and the areolated appearance of B.M. 2 united in one single specimen. In 

 1949 and 1988 (both dry !) we observe the same 1 ). 



In several specimens the surface is glabrous or subglabrous and rather glossy. We find it on 

 the whole in specimens of trop. tegens, trop. pyramidalis, trop. digitata and trop. tuèerosa, whereas 

 we do not see it in specimens of trop. concrescens, trop. glaebosa and trop. tuöulifcra, which are 

 more or less hispid by slightly projecting tylostyli. It is, however, not a rule without exceptions. 



The size of Spirastrella pitrpurca differs as much as the shape. In the follovving table 

 I have arranged the specimens according to the tropi. 



Specimen 



Author 



Size in centimeters (height first) 



Remarks 



1945- • 

 B. M. 33 

 B. M. 15 

 B.M. 2 

 426 c . 

 426 b . 

 1988. . 

 B.M. 7 



92 a . . 



92 b 



92 c 



92 d 



92 e 



92 f 



92 g 



92 h 



92 i 



92j 



g2 k 



92 1 



426 d 



B. M. 37 



B.M. i6(?) . . . . 

 Spirastrella insignis . 

 Spirastrella cunctatrix 

 Spirastrella cunctatrix 



Carter 



Carter 



Dendy 



BOWERBANK 



Rdl. & Dy. 

 Carter 

 Thiele 

 Carter 



Carter 



[9X15x5 (thickness) 



38 x 13x25 

 15x13x18 

 1 9 X 11 X 20 



7 X 7 A7 

 9x10x12 

 8x12 x 14 



240 cm. high 



9.5 x6x II. 5 



11 X8 X 15-5 



15 ■' 8X10 



12 x 5.5 X 10.5 



7-5 ■: 5 X 7-5 



9 ■ 5-5X9-S 



8x4-5x9 



10x7x7 



12X4-5 X 12 



7 x 4-5 X 6.5 



4x2.5 X3-5 



9.5 x 4-5x7.5 

 7x4X5 



15 x 10 (X 10?) 



17.8 X 15 X 20 



24 X 19 X? 



7.6 X 7.6 X 23 

 9x9X5 



1) The same phenomenon I often observed in massive forms of Cliona celala. 

 SIBOGA-EXPED1TIE Vla 1 . 



crust ; 1 — 10 mm. thick 



