EUSYLLIS BLOMSTRANDL 177 



Head sub-rectangular, with the angles rounded. Eyes four, forming a rectangle, and 

 according to De St. Joseph, with a pair of oculiform touches in front. Palpi somewhat 

 ovate. Median tentacle longer than the lateral, indistinctly articulated. Tentacular 

 cirri of similar shape, the dorsal of the first pair exceeding the length of the tentacle. 

 At the base of the head is a patch of cilia on each side. The tips of the tentacles, the 

 tentacula, and the first dorsal cirri, are coloured brown (De St. Joseph). 



Body of an orange hue, about five eighths of an inch long, but incomplete in the 

 examples, and having the typical shape. The dorsal cirri become shorter than the 

 breadth of the body after the fourth. Two caudal cirri at the tapering posterior end. 

 Proboscis with a single tooth at the tip in extrusion, and a series of papillse behind it. 

 The proventriculus has fifty-five rows of points, and the lateral pouches of the ventricle 

 are small. 



The foot has dorsally the short cirrus, then a bluntly-conical, setigerous region, with 

 the tips of the spines l pointing to the upper angle. The bristles (Plate LXXIX, fig. 2) 

 have slightly curved shafts, with traces of serrations on the bevelled region at the tip 

 and the convex edge of the dilatation. The terminal piece is of moderate length and 

 nearly equally bifid at the tip. Slight variations in the length of the terminal piece occur 

 in different specimens from the Minch. The ventral lobe is somewhat ovate and does not 

 quite reach the tip of the setigerous region. 



De St. Joseph 2 (1887) found an abnormal example with three proventriculi. The 

 median was normal in position, whilst the two lateral were posterior to the former and in 

 the situation of the lateral cseca, which in this case were minute. If no misinterpretation 

 occurred the condition is remarkable. 



An elaborate account of this form is given by Marenzeller (1894) from examples 

 procured in the Ostspitzbergen Expedition of Kukenthal and Walther in 1889. He 

 figures in some of these the enlarged distal end of the shaft spinous along the bevelled 

 edge, and in others hispid with small spikes over the dilated region. 



A fragmentary specimen from the South- West of Ireland (Royal Irish Academy's 

 Expedition, 1885) appears to correspond with the foregoing species. The dilated and 

 bevelled ends of the shafts of the bristles, however, show the minute spines less distinctly 

 either from their removal by friction or otherwise. This also is a female laden with ova, 

 and swimming-bristles are developing below the dorsal cirrus. 



Eusyllis monilicomis of Malmgren is a very closely allied form, and further examina- 

 tion may explain certain points of divergence, as, for instance, in the description of 

 De St. Joseph, for it differs from the type in Malmgren's paper. 



Malaquin, though he did not ascertain the precise details of the early history of the 

 eggs and larvse of Eusyllis monilicomis, found young forms abundant on the tufts of 

 Polyzoa (Membranijoora), showing no movements, devoid of cilia, and enveloped in a 

 vitelline membrane. Each presents two eyes, and a larval pharynx abutting on a 

 vitelline mass differentating into an intestine. These are of interest in relation to 



1 De St. Joseph gives these a curved tip (as in Sylline), but such was not seen in the 

 foregoing examples. 



2 De St. Joseph, op. cit., p. 172, pi. viii, fig. 39. 



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