I04 The Irish Natu7alist, May, 



The hooks are figured by v. Graff (see figs, ii and 12), as 

 having the terminal process of the shaft strongly serrated. 

 In none of my specimens could I see any sign of such serra- 

 tion (fig. 5). In this respect again my specimens differ from 

 V. Graff's species. 



Size — Johnston's specimen was about 12*5 mm. long. V. 

 Graff gives the size of his species as follows : — Length 1 1 -4 mm. 

 to 26 mm. ; average proportion of length to breadth ^j . The 

 average length of 22 of my specimens which were in good 

 enough condition to measure at all accuratel}^ was 8'i mm., 

 the specimens ranging from 4*8 mm. to 13 mm. The average 

 measurements of 7 of my best specimens were : — length 9*28 

 mm., breadth 6*93 mm., average proportion of length to 

 breadth If^ 



Von Graff's measurements of 22 specimens oi S. miniaceus, 

 ranging from 0*9 mm. to 8*5 mm. in length, give the following- 

 averages : — Length 4"65 mm., breadth 3-05 mm., average pro- 

 portion of length to breadth j?. 



►S*. ardicus ranges from 22 mm. to 50 mm. in length ; average 

 proportion of length to breadth ~. 



Number of Segments. — Johnston described his specimen 

 as having "about 30" segments, but in his figures he shows 

 only 21 rows of lamelicC and 26 or 27 pairs of parapodia. Von 

 Graff gives the number of parapodia in his species as 48 pairs. 

 I have never seen more than 26 pairs, the majority having 

 from 20 to 25. S. miniacetis has 12 to 24 pairs of parapodia, 

 6". ardicus up to 50 pairs. 



Here again my specimens agree with Johnston's description, 

 but differ considerably from the species described by v. Graff. 



The Ventral Surface. — A point included by v. Graff in 

 his diagnoses is the appearance of the ventral surface. Of his 

 S. oniscoides he says : — " Ventral surface provided with warts, 

 which are scattered in a median area, and from there extend 

 to the bases of the parapodia in thickly packed, tumid, elevated 

 stripes, separated by wartless intervals." This agrees very 

 closely with the appearance shown by my specimens, in some 

 of which, however, probably owing to bad preservation, the 

 warts are difiicult to detect. The lack of warts, which occur 

 also in 6*. ardicus, is one of the diagnostic characters of S. 

 miniaccus. 



