38 Transactions. 



The penial ehaeta (fig. 5) is slender, curved, and slightly swollen just 

 below the apex, whose sharp point is slightly bent up to form a hook ; 

 it has no perceptible furrow. The sides are not ornamented by rows of 

 minute teeth as in M. michaelseui, but in certain lights some five or six 

 faint transverse lines can be made out just below the swollen region. 



Locality. — DUrville Island. 



Remarks. — This species certainly has some resemblances to M. michael- 

 seni, especially in the possession of a depression on the segments 17-19. 

 But from it the present species differs in one or two features that seem 

 to be specific. The gizzard, which in that species is said to occupy the 

 two segments 6 and 7, here lies only in the 6th. I was careful to trace 

 out the septa as above described. 



The oesophageal glands, four in number, are said by Ude to be " small." 

 The penial chaetae are described as " long," " spoon-shaped," and orna- 

 mented with very fine teeth in transverse rows ; and, though the tip is 

 curved, its curvature is in the other direction, and there is no swelling below 

 the apex. Thinking that perhaps this last feature was due to pinching 

 w^ith the forceps, I examined a " reserve," or undeveloped, ehaeta, which 

 I find exhibits the same subterminal enlargement. 



Ude also speaks of the penial sac as being " absent." I have noted 

 its very small size, and it may be that in a well-hardened specimen it 

 would not project within the body- wall. 



Had it not been, however, for the distinctness between the form of 

 the penial chaetae in the two forms, I should have regarded this as merely 

 a variety of Ude's species. 



Perieodrilus durvilleanus n. sp. 



A single individual was received, which unfortunately is immature. 



A brick-red worm, with its mid-dorsal line of much deeper tone than 

 elsewhere ; each segment is marked by a number of white spots, in each of 

 which is a ehaeta. 



Length, 108 mm,; diameter, 6 mm,; with 117 segments. The body 

 is cylindrical, with scarcely any tapering at the hinder end. 



The prostomium is tanylobic. 



There are some 20-24 chaetae on each side of each segment. They 

 are not in definite couples, but are more or less equidistant, though here 

 and there a ehaeta is absent. 



The dorsal '" gap " is about one-third the width of the ventral gap. 



Dorsal pores are present, but I failed to note at what segment they 

 commence. No nephridiopores are visible under the dissecting-lens, owing, 

 I believe, to the softness of the wall. 



There is no sign of a clitellum. On the 17th and 19th segments, 

 outside the ventralmost ehaeta on each side, is a faintly expressed papilla, 

 recognizable in its immature condition by its pink colour in contrast 

 with the nearly white colour of the surrounding skin. No spermatic groove 

 is as yet present. 



Internal Structure. — The septa behind the segments 9 to 13 or 14 are 

 thicker than the rest 



The dorsal vessel is double throughout the worm ; enlarged hearts 

 in 10th to 13th segments. 



The gizzard is long, lying apparently in the 7th and 8th, but in reality 

 it belongs to the 6th and iiossibly partly to the 7th. 



