4 ARKIV FÖR ZOOLOGI. BAND 7. NiO 5. 



Size. 



The length of the type specimen was given by Kinbero 

 as 395 — 400 mm. On measuring the specimen I found it to 

 be about 405 mm. in length of which the tail represents about 

 155 mm. The symbol »Vi», ^y the side of the figure of 

 this worm on the unpublished plate. indicates that the figure 

 is natural size, but, on measurement, it is found to be 475 

 mm. long of which the tail is about 200 mm. The figure is 

 therefore larger than natural size and does not accurately 

 represent the relative proportions of the body and tail of the 

 specimen. 



The measurements of the specimens from Saldanha Bay 

 are as follows: 



5 mm. of which 



The largest of these most closely approaches the type 

 specimen in size and in the proportion of its body and tail. 

 It is, hov/ever, rather shorter and somewhat stouter in the 

 body region than the type; its tail is the. same length as, 

 but thicker than, that of the type specimen. The diameter 

 of the type is given by Kinberg as 20 mm.: the specimen 

 was probably measured near the third or fourth chaetigerous 

 annulus, where it is widest; its girth at the 4th chaetigerous 

 annulus is now about 60 mm. Specimen No. 4, from Saldanha 

 Bay, measured at the level of the fourth chaetigerous segment, 

 where it is thickest, has a diameter of 23 mm. and a girth 

 of 68 mm.; the diameter and girth of the middle of the tail 

 are 16 mm. and 50 mm. respectively. 



Although of such massive proportions, A. loveni is not 

 the largest species of the genus; it is surpassed in size by 

 Ä. cr.istata Stimpson, and is equalled, at any råte in length, 

 by A. marina (L.). The largest specimen of Arenicola known 

 to me is an example, in my possession, of A. crisiata, from 

 Woods Hole, Massachusetts, U. S. A., which is 515 mm. in 

 length (the tail being 190 mm. long). and 75 mm. in girth at 

 its widest point. Examples of A. marina 350 to 400 mm. 

 long are occasionally found, the anterior region of which may 

 attain a girth of about 70 mm., but their tail region is usu- 



