MALDANIDJE. 291 



and neurilemma on each side of the middle line above the nerve area. The foot is pushed 

 far upward, and thus these bristles are at the dorsal attachment of the oblique. The 

 dorsal longitudinal muscles are separated by the dorsal blood-vessel, the mesentery from 

 which is fixed to the upper arch of the alimentary canal. They form a lobate area with 

 the broad end downward on each side of the alimentary canal, whilst a separate slip, 

 triangular in section, lies between its upper border and the origin of the oblique. The 

 ventral longitudinal muscles are of great proportional bulk, and stretch from the nerve- 

 cords to the dorsal origin of the oblique muscles, a narrow fasciculus, however, filling the 

 gap at the lateral blood-vessel. The alimentary canal has external circular and longitu- 

 dinal muscles, and a thick glandular mucous lining thrown into numerous folds. Beneath 

 is the ventral blood-vessel. The nerve-area is hypodermic, of ovoid or slightly spindle- 

 shaped outline, and with a large neural canal in the middle line superiorly. Externally is 

 a considerable sheath of neuroglia, the cells of which stain more deeply than the hypo- 

 derm. Between the attachments of the oblique muscles is the ventral blood-vessel. 



In Praxillella pr&termissa the hypoderm, which has externally a thin cuticle, is as 

 largely developed as in Nicomache, and inside the basement-membrane is a well-marked 

 circular coat. The dorsal longitudinal muscles have somewhat increased in size and each 

 is contiguous, in transverse section, to the dorsal origin of the oblique. The ventral longi- 

 tudinal are long and clavate, the larger end in section being ventral, thus forming a bulky 

 mass over the outer end of the nerve-cord on each side of the attachment of the oblique. 

 The nerve-area is ovoid or flattened, with a large median neural canal superiorly. 

 Interiorly is the circular muscle, externally only the hypoderm and cuticle. 



The body-wall in Praxillella gracilis has a similar hypoderm and cuticle to the 

 foregoing, but in proportion to the ventral the dorsal longitudinal muscles have somewhat 

 increased in size, whilst the bulky ventral longitudinal almost touch in the mid-ventral 

 line. The nerve-area holds the same position, is somewhat less flattened, and has many 

 deeply-stained cells of the neuroglia around it. Moreover, no neural canal is visible. The 

 ovarian sac on each side of the alimentary canal is distended with large ova. 



In transverse sections of Maldane Sarsi, var. of the ' Challenger ' Expedition, the 

 quadrate nerve-cords have moved inward and lie between the inner ends of the somewhat 

 extended ventral longitudinal muscles, the thin circular fibres bending inward with them, 

 whilst the oblique are attached to the upper and outer angle, and there is no neural canal. 

 In this example the sperms occupy the general coelom. 



0. P. Midler's 1 (1788) Lumbricus tubicola is evidently a Maldanid, but there is nothing 

 definite in either figure or description to diagnose the species. 



On Plate CIV the same author figures a Maldanid in a tube — possibly a broken Axiothea 

 or Praxillella. He calls it Lumbricus sabellaris. 2 It is truncated at either extremity, 

 the anterior segments are shorter, especially the first four. Posteriorly are seventeen 

 or eighteen longer segments. He observes that one end has a denticulated funnel, whilst 

 the other is attenuate and truncate. It somewhat resembles Nicomache. 



The Maldanies of De Blainville formed the first family of his Paromocriciens, the second 

 being Telethusao. These were supposed to have a thoracic and abdominal region. His 



1 'Zool. Dairica/ vol. ii, p. 49, Tab. lxxv. 



2 Ibid., iii, p. 37. 



