180 PBTGH : 



2.—Aserof' arachnoidea, Ed. Fischer. 



This species is said by Fischer to differ from A. rubra, La Bill, 

 in that its arms are one-chambered, and are*prodiicfid into a 

 long flagellum. The flagellura is certainly not as long as in 

 some examples of .4. rubra. Penzig, who found it fairly 

 common in Java, says that it differs from the numerous forms 

 of rubra in its white colour, and its one-chambered, less numer- 

 ous arms, which are not arranged in pairs. As Aserof' rubra 

 forma zeylanica usually has the arms not arranged in pairs, 

 the last point of distinction is invalid. The chief differences 

 between the two species appear to be (1) the colour, (2) the 

 structure of the arm, and (3) the arrangement of the arms in 

 the egg. The arm of ^4. a,rachnoidea is one-chambered and 

 has two longitudinal ridges, united by cross ridges, on the 

 ventral surface, and often a longitudinal furrow on the dorsal 

 surface : the arm of A. rubra is composed of many chambers and 

 is smooth externally. In the egg the arms of A. arachnoidea 

 are closely applied to, but do not hide the gleba, and meet in 

 a point at the upper pole, while the arms of A. rubra hide the 

 gleba completely and are prolonged down the middle of the 

 egg, twisted into a column as previously described. 



I have only met with this species once. The specimens had 

 been torn up by the reajjer when cutting grass at Peradeniya, 

 and they were considered at the time too damaged to photo- 

 graph. Three eggs were united in a cluster by the fusion of the 

 volvse. The volva is spherical and white. 



The only expanded specimen was 3 cms. high with an almost 

 uniform stalk, 1 cm. diameter. The wall of the stalk consists 

 of two layers of chambers, the inner of which are much larger 

 than the outer, as in Simbhmi periphragmoides , and, as in the 

 latter species, the inner chambers form, in some parts, con- 

 tinuous tubes extending into the arms. The wall of the stalk 

 bends out horizontally at the top for a distance of about 3 mm. , 

 and then divides into narrow arms about 1 ' 5 cm. long, taper- 

 ing to the apex. My three specimens have 11, 12, and 13 

 arms r(>spectively. Penzig says that the number of arms 

 varies from seven to thirteeJi, but that the commonest number 

 is nine. 



