47 18 Proceedings of the Royal Irish Acadenv/. 



in a triangle. The specimens from Clew Bay have also small eyes, but one 

 from Lough Swilly has very large eyes, and the pigment on each side is 

 continuous. The arrangement is, however, the same. On the outer side of 

 the eyes are conspicuous ciliated nuchal organs. The palps are large and 

 conical, completely fused on the dorsal side, but showing a shallow median 

 groove on the ventral surface. The brain is elongated and bilobed. 



The buccal segment is as large as the head, and has a pair of small 

 bulbous tentacles tipped with stiff cilia. The first setigerous segment is 

 normal, and the second is, as usual, without dorsal cirri. 



The anal segment (fig. lc) has two slender cirri and a median papilla. 



The feet are very similar throughout the length of the body. The 

 setigerous lobe (figs. Id, 1e) is unequally bilobed, the dorsal portion contain- 

 ing the aeiculum being much the smaller, and having a rounded papilla near 

 the tip. The dorsal cirri are small and bulbous, with stiff cilia at the tip. 

 The ventral cirri are cylindrical and much larger than the dorsal cirri. Each 

 foot contains 4-10 compound setae in a fan-shaped series, with the tips 

 pointing upwards. The shaft (If, b) is slightly curved, swollen, and bevelled 

 at the tip. The terminal pieces vary very little in size, the longer tips being 

 in the centre of the series. They are coarsely toothed on the basal portion ; 

 and some distance below the tip is a broad tooth which gives them a bifid 

 appearance. The tips of the setae are rather shorter in the two anterior 

 segments than in those behind. There is a single spine ending in a swollen 

 smooth tip (fig. If, c). In the type specimen a simple dorsal seta appears in 

 the seventh foot and is joined in the posterior seven segments by a similar 

 ventral seta. These setae are curved and pointed, with a conspicuous tooth 

 below the tip (fig. If, a). The ventral seta is slightly thinner than the 

 dorsal one. The disposition of these simple setae varies considerably. In 

 a specimen from Clew Bay the dorsal seta is present in all the feet, and 

 the ventral seta commences in the 10th foot. A similar arrangement is 

 found in a specimen from Blacksod Bay. 



The proboscis (fig. 1a) extends from the 2nd to the 5th setigerous 

 segment. It is covered with dark pigment, except for a narrow strip in the 

 4th segment. The anterior part of the proventriculus is long and narrow, 

 occupying nearly two segments, and has 25 rows of glands. There is a 

 constriction between it and the next portion, which is muscular, without 

 glands. Into its posterior end open two small ciliated sacs (fig. 1h) . The 

 proboscis has 10 soft papillae in front, and a conical tooth (fig. 1a, 1g). The 

 specimen from Galway Bay is a female, with two eggs in each segment from 

 the 10th to the 22nd, and was collected in May. Through the kindness of 

 the authorities of the 17. S. National Museum, I was able to examine several 



