536 Miscellanea Zoologica. 



the tail, of an olive or yellowish colour, the latter tint most predo- 

 minant in front, which is marked with a black spot of a quadrangu- 

 lar form, and 4 eyes placed nearly in a square. It was in this 

 species that the structure peculiar to the <renus was most easily to 

 be traced. 



5. N. ptdchra, linear-elliptical ; of a flesh-red colour, with a se- 

 ries of scarlet spots along each side, or of a uniform aurora- 

 red ; eyes numerous, unequal. Plate XVII. Fig. 6. 

 Hab. Amongst corallines, and in old shells, &c, in deep water. 



Coast of Berwickshire, frequent. 

 Body about an inch in length, and two lines in breadth, compres- 

 sed, narrow, elliptical, the front marked with numerous black specks, 

 irregularly arranged and visible with the naked eye. Many speci- 

 mens are of a uniform aurora-red colour, considerably paler on the 

 ventral aspect, while others are beautifully marked along each side 

 with a series of large scarlet spots ; the former are perhaps males, 

 or more probably individuals in a barren condition, while the others 

 seem to be full of mature ova, for an examination of the spots through 

 the microscope shows that they are produced by clusters of oviform 

 bodies lying in the interstices of the ccecal appendages. 



This and the first species contrast remarkably in their form, and 

 show the extremes to which this character is subject. The structure 

 of the stomach is like that of its congeners, excepting in there being 

 five or six spines on each side of it, instead of three, which is the 

 usual number. Immediately under the hearts, we observe a large, 

 somewhat muscular viscus, apparently hollow, and lying in the course 

 of the intestine, but apparently unconnected with it, for in the indi- 

 vidual which served for our figure, the intestine had been extruded 

 from the body, and entirely expelled by the contortions of the worm 

 produced by impure sea-water. Of its office and nature I can offer 

 no opinion, but I may remark that in all the species a greater dus- 

 kiness in its site shows that a similar organ exists in all. 



* * Alimentary canal apparently homogeneous throughout. Sub- 

 genus, BoRLASIA * 

 6. N. olivacea, of a dark olive colour ; eyes four, placed in a 

 square. Plate XVIII. Fig. 1. 



* A name given by Oken to the Lineus of Sowerby, co-equal therefore with 

 the Nemertes of Cuvier, equally unnecessary, and as originally applied altogether 

 inadmissible. Because it commemorates a worthy naturalist, Dr William Bor- 

 lase, author of the History of Cornwall, I rejoice in being able to affix it to a 

 group hitherto uncharacterized. 



