Gutty Marine Luhoratonj , St. Andreics. SO 



region of the body not yet having been reproduced, whilst 

 tlie caudal process is fully developed. 



The lamellar hooks have six teetli from the crown down- 

 ward, then a finely spinous process (like a large tooth with 

 serrations), below which is a notch directed ujiward^ and, 

 lastly, the rounded prow, which is nearly in a line with the 

 face of the hook. The shaft of the hook is short and 

 comparatively broad. 



The tube is gently curved and finely tapered, especially 

 in the smaller specimens, and composed of fine sand- 

 grains neatly cemented together, the tubes of young forms 

 especially having very minute grains. In the ' Poicupint; ' 

 Expedition of 1869 empty tubes apparently of this species 

 were formed of ti'ansversely arranged and neatly cemented 

 sponge-spicules. In specimens from deep water, 80-180 

 fathoms, in Hardanger Fjord and off Leavig in Norway the 

 tubes at first formed of fine sand-grains were for some 

 distance afterwards formed of sponge-spicules placed trans- 

 versely. 



In extremities a Nemertean ((jne of the Aopla) will occa- 

 sionally thrust itself in the mouth of the tube, driving the 

 annelid before it and compressing it in the posterior region 

 of the tube. 



The third species, Lagis horeni, Malmgren, has often been 

 mistaken for Pec/irtorm belyica. In this generally distributed 

 form the head is provided with a transverse series of fifteen 

 lustrous golden paleolse on each side. Each is a flattened, 

 hollow, chitinous process tapering to a delicate tip, which is 

 always more or less curxed toward the dorsum, the con- 

 cavity of the curve or coil being mintitely crenulate. as if 

 from a thinner tissue on that side. Moreover, the point of 

 those in the middle of the series is continued as a long and 

 delicate process — generally coiled. The outer in each series 

 is short, broad at the base, and with a long tapering tip — 

 not coiled. The paleolse are finely striated longitudinally, 

 and also marked by transverse lines. The second external 

 paleola has its transverse lines arranged in distinct ringed 

 belts, and not scattered indiscriminately. In viewing the 

 paleolae of each side as a whole, the distal curve of the outer 

 forms is more marked than that of the inner forms, and the 

 inner are deeply set in the tissues and moved by powerful 

 muscles, whereas the external paleolse are less deeply im- 

 planted. The bases of the paleohe have a slight obliquity, 

 being diiected downward and outward on each side. In 

 transverse section the flattened hollow cor:dition of the 

 paleolse is a])parcnt. Moreover, they become much thinner 



