434 H. Lyster Jaineson 



fortunately lost, but was figured from life by C. Merculiäno on 

 23''^ Januaiy 1886. This colour sketch is bere reprodueed (PI. 13, 

 fig. 1). The other example was veiy generously handed over to me 

 for examinatiou by tbe authorities of the Station, it is accompanied 

 by a label witli the following data — »Preso colla tartanella nel 

 fango 1 miglio fuori Nisida; Alcohol 70^. 10. 3. 1882.« — D^ Lo 

 Bianco iuforms me that the 1886 example was dredged in the same 

 locality, and that both were at a depth of 30—40 Meters. 



The example that I dissected presents no character which War- 

 rants its Separation from the genus Tìicdnsscma, in which genus, as 

 will be seen from the anatomical description, it occupies a position 

 nearer to Tlialassema diaplianes of Sluiter (10) than to any other 

 known species, if the characters usually relied upon for systematic 

 purposes (longitudinal musculature, number of segmentai organs, 

 form of anal pouches) are real evideuces of affinity. 



The length of this example was 70 mm , the average breadth 

 12—15 mm; but there can be no doubt that the living worm can 

 extend itself considerably more ; Merculiano's colour sketch is life 

 size and measures 93 mm in length, while Delle Chiaje's drawing 

 (l, Tav. 106, fìg. 19] is referred to in the description (pag. 124) as 

 »di giusto diametro, delineato morto e supino«. This figure is 

 150 mm long. 



These three examples ali lacked the proboscis, but I bave 

 determined, by means of sections of the small remaining stump, 

 that normally a proboscis is present, as in the stump the nervous 

 and blood-vascular Systems are incomplete ; indeed, without sections, 

 the three holes, corresponding to the blood-vessels, Avere visible on 

 the scar. 



The body is sausage-shaped, the posterior end much rounded, 

 and obtuse, the anterior end more pointed. Along the mid-ventral 

 line is a shallow groove, marking the position of the nerve cord, 

 which, in the middle third of the body, can be seen shining through 

 the transparent integumeut. 



As in ali Echiuroids the mouth and anus are terminal. The 

 openings of the two segmentai organs are about 2 mm apart, and 

 about 2 mm behind the pair of ventral hooks or bristles. The brist- 

 les had fallen out in the example that I dissected, but I could 

 without difficulty deteimine their former position; the depressions in 

 the skin that they had occupied were quite obvious, and the skin 

 itself contained the usuai »Ersatzborsten«. The hooks must bave 



