HERMELLID^E. 3 



Fuchs (1907) describes in Sabellaria alveolata the blood-sinus round the gut as 

 ending posteriorly in a thick dorsal vessel, and in front in the heart. The ventral vessel 

 is median anteriorly, asymmetrical in the abdominal region. The vasa lateralia are largely 

 developed, furnishing blood to the gills. The intersegmental ring-vessels are on the 

 anterior face of the respiratory dissepiments. 



Arnold Watson notes that in the fifth segment of Sabellaria alveolata a transverse 

 muscle pulls the bristles closely to the side of the annelid, and another slip which crosses 

 the cavity of the foot from front to rear acts in that direction. 



This author has, with long-continued enthusiasm, observed the structure and functions 

 of many organs in the tubicolar polychgets ; thus he noted that the proventriculus (gizzard) 

 in Sabellaria prepared the food for considerable periods, the grains being moved up and 

 down by muscular contraction from end to end, even occasionally being forced into the 

 dark part of the gullet or the commencement of the intestine, but always returned to the 

 gizzard for further treatment. According to this observer, the blood from the intestinal 

 sinus at the posterior end of the crop spreads out, passes over the organ (crop) in capillaries, 



SDTTV 



Fig. 137. — Transverse section of the posterior region (near tip of tail) of 8. spinulosa, Leuck. d, alimentary- 

 canal ; dm, dorsal longitudinal muscles ; nc, nerve- cords ; spm, sperms. 



and collects in front of it in large lateral patches (re-forms vessels). The pear-shaped 

 region in front of the crop has the two lateral trunks connected by transverse branches. 

 The ventral trunk seems to fork at the tip of the caudal appendix and curve forward to 

 form a lateral vessel on each side. He also saw a vesicle on the face of a septum (of the 

 abdomen) which contracted horizontally, and so with the circular veins. The ventral 

 trunk gives off lateral branches in each abdominal segment which go to the contractile 

 bulbs. He thinks the same arrangement is continued in the caudal appendix without the 

 " ring " mentioned by De Quatrefages at the junction of the caudal appendage and the 

 " abdomen." The two lateral trunks or sinuses (one on each side) pass forward to the 

 crop, giving off in each segment transverse trunks to the branchiae, three being rather close 

 together behind the crop, where they are lost. In front of the crop, round which a very 

 fine blood-vessel runs, a lateral vessel again appears on each side, but soon joins into a 

 median dorsal heart which has a heart-body, the vessel then going straight to the bases 

 of the palea3. Lateral trunks are given off to the branchiae. Posterior abdominal 

 (afferent) branches pass from the lateral trunks, which are in a line with the dorsal 

 vessel, to the branchiae for nine or ten segments in front of the caudal appendage. In 

 the abdominal appendage of a translucent specimen the median vessel appeared to be 



