BY N. A. COBB. 397 



backward into a uterus ten times as long as the body is wide, 

 and containing two segmenting eggs each four times as long as 

 the body is wide and one-fifth as wide as long. In the uterus 

 are granular spermatozoa of a spherical shape, and of such a size 

 that eight of them placed side by side would reach across the 

 body. The reflexed part of the ovar}^ reached three-fourths the 

 way back to the vulva and contained numerous developing ova 

 arranged in single file. 



This worm, of which I have seen only the female, was found in 

 mud below low-tide mark. Port Jackson, New South Wales, 

 Australia. 



Plectus, Bastian. 



1-.5 10-5 20- '48'^^ 92- ,.- 



P. PARIKTINUS, Bast., var. austraUs. x-a 3-7 4-6 5^6 2^t ° '"™" 

 The transparent cuticle is transversely striated, there being about 

 seven hundred strife in all on the worm. The body wall is nearly 

 one-fourth as thick as the worm itself. Very inconspicuous 

 papilla like setfe occur throughout the body. The neck contracts 

 more rapidly anteriorly where it is convex-conoid, ending in a some- 

 what truncate head bearing six distinct sub-spherical lips, each 

 bearing at least two very inconspicuous papillae. The lateral organs 

 are unclosed ovals about as wide as the cephalic setae are long, 

 placed opposite the middle of the pharyngeal cavity. The cephalic 

 setae are of equal size and are four in number, and are arranged one 

 on each submedian line at the base of the lips; they grow at right 

 angles to the cuticle and have a length about equal to the dia- 

 meter of one of the lips. There are no eye-spots. The comjDound 

 pharynx is composed of two parts, of which the first is that 

 referred to in the formula (as 1'5); this is again duplex in struc- 

 ture, being wider in the anterior half than in the posterior. A 

 slight stricture in the outer contour of the pharyngeal tube marks 

 the beginning of the posterior part of the pharynx which contains 

 what appears to be a narrowly fusiform cavity as long as the 

 duplex cavity just mentioned, the entire pharynx therefore 

 occupying nearly one-fourth of the length of the neck. The 

 cylindroid cesophagus, scarcely one-third as wide as the neck, ends 



