STAUROCALYPTUS PLEORHAPHIDES. 225 



may be rounded while the other is as usual acutely pointed, as 

 e.g. in some of those diaetins that just reach the dermal surface 

 with one of their tips, in which case it is the distal end which 

 may be rounded off (PL XVI., fig, 14). 



The smaller parenchymalia, including the fine comitalia, are 

 of the usual appearance. They seem to grade down in dimensions 

 uninterruptedly to the small diaetins which I shall describe 

 further on as the gastralia. 



The j:)ro.?/a/ diaetins, which are in fact to be regarded as 

 enormously developed parenchymal principalia, are of various sizes. 

 A small one may measure only 10 mm. in length, while the 

 largest measured was 40 mm. long and 253/'- thick. The needle- 

 like spicules are straight or nearly straight, tapering perceptibly 

 towards both ends. The outer end is usually found to have been 

 broken off; the inner is either acutely or bluntly pointed, the 

 subterminal surface being smooth or sparsely beset with micro- 

 tubercles. The entire exposed surface of the prostat needles, — at 

 least, of the larger of these, — is minutely and densely rough, in 

 exactly the same way as the paratangentials of certain prostal 

 pentactins soon to be described. The roughness extends a short 

 distance into the parts rooted in the sponge-w^all, gradually 

 fading into a perfectly smooth surface. The parts in the wall, as 

 also the same parts of the shafts of hypodermal and prostal pentact- 

 ins, are generally accompanied by some comital parenchymalia. 



The hypodermal pentactins are somewhat variable in size. 

 The paratangentials, which are generally not quite straight but 

 rather wavy, may be 5 mm. long or longer. The straight shaft 

 or the unpaired proximal ray is always much longer than the 



