Gaify Marine Laboratory y St. Andrews. 153 



congenial to the animal than with mudj which at least 

 enables it to separate the long coiled filaments. 



The peristomial segment is somewhat narrower than the 

 two which follow, and each of which has various transverse 

 creases or wrinkles. These are devoid of bristles, hooks, or 

 other appendages. The first setigerous segment follows the 

 foregoing and is broader than its successors. The foot is 

 represented in the lateral region only by dorsal and ventral 

 setigerous processes, which bear tufts of capillary bristles. 

 Moreover, near the junction with the segment behind and 

 nearly on a level with the upper bristles is a long coiled 

 branchia. The capillary bristles have somewhat stout shafts 

 and long, flattened, tapering tips, with a narrow border of 

 spines directed distally. The four or five bristled segments 

 which follow are broader than those next them, but all have 

 the capillary bristles dorsally and ventrally. In the groove 

 between the second and third bristled segment a second and 

 smaller branchia occurs, the base arising a little above the 

 level of the dorsal bristle-tuft. The same takes place in the 

 groove between the third and fourth and between the fifth 

 and sixth. The branchise and tentacles vary in size according 

 to the degree of development, those in process of reproduc- 

 tion being small, whilst the older examples are thick. All 

 are minutely ringed, probably from muscular fibres. 



The strong hooks commence in the ventral series of the 

 large examples from Plymouth at the sixty-second bristled 

 segment, though they vary in this respect^ some commencing 

 at Ihe forty-fifth, others at the sixtieth. The hooks are at 

 first slender, but soon become robust, the neck curving 

 backAvard and then forward at the tip, and probably they are 

 the main agents in securing a firm hold of the burrow. 

 Their appearance in the dorsal division is somewhat later, 

 viz. between the ninety-first and ninety-fifth bristled seg- 

 ments. In both cases the foregoing figures diflFer from those 

 of von Marenzeller and De St. Joseph. The former states 

 that the first ventral hooks appear in C. tentaculatus between 

 the thirty-thitd and forty- fifth segments, and the dorsal 

 between the fortieth and forty-fourth ; whereas in Cirra- 

 tulus chiajii the ventral appear between the twenty-first and 

 twenty- third and the dorsal between the fortieth and forty- 

 fourth. The variation in regard to the appearance of these 

 structures in British examples of C. tentaculatus would also, 

 as De St. Joseph observes, lead to some doubt as to specific 

 identity based on this feature. 



An examination of two examples of Cirratulus {Audouinia) 

 fil'iyerus from Naples shows that in one the anterior tentacles 



