1909- RiDDHLT.. — Spinther ofiiscoides, Johnston. 103 



Cirri. — In figs, i and 2 I have drawn parapodia with cirri. 

 For purposes of comparison I have also shown, after v. Graff, 

 a parapodium from S. ininiaceiis (fig. 7) and one from v. Graff's 

 5. 07iiscoides (fig. 8). 



It is evident from these figures tliat we are here dealing 

 with a species each of whose parapodia bears a dorsal cirrus ; 

 this character would of itself be sufficient to distinguish this 

 species from S. niiniacetts and S. ardicus. The possession of a 

 parapodial cirrus was one of the points mentioned by Johnston 

 in his description, the '• large bulb " which he described being 

 the parapodium. 



SET.^i. — Johnston described the setae of his specimen as 

 follows :—" The bristles are of three kinds; viz. (i) the spinous, 

 sharp and fashioned like a needle ; (2) the forked, which are 

 fdiform with a bulbous root, and cut into two scarcely equal 

 prongs at the apex ; and (3) the clawed, a bristle which has a 

 stem slightly incrassated upwards, where a strong curved and 

 sharp claw is articulated by an oblique joint. The forked 

 bristles are the Diost numerous ..." 



Von Graff sa5\s that in his kS". oiiiscoides the setae of the 

 dorsal lamellae are mostly one-pointed, but two-pointed forms 

 also occur. 



I have been unable to satisfy myself as to the occurrence, 

 in my specimens, of any one-pointed dorsal setae; the only 

 sharp-pointed setae are those included in the parapodia. It 

 will be noticed that Johnston, in contrast to v. Gi-afif, says the 

 " forked bristles " were the commoner, but he says nothing as 

 to where each kind occurred. Even if he did include sharp- 

 pointed forms among the dorsal setae, I think this is 

 attributable to deficient magnification. I have on several 

 occasions had to employ a magnification of 250-350 diameters 

 to make sure that a given spine was really two-pointed. In 

 figure 4 I have drawn two views of the same seta. The one 

 is magnified 80 diameters, the other about 400 diameters. It 

 will be seen that the high-power view shows a distinct second 

 point, in fact this seta is comparable to the upper one of the 

 three shown in fig. 3. 



In this respect, then, my specimens do not agree with 

 V. Graff's, and v. Graffs description is also opposed to 

 Johnston's. 



A 2 



