BY N. A. COBB. 403 



hammer-shaped, being of the sort that possess a backward pointing 

 process, which is here arcuate. The ejaculatory duct begins at a 

 distance from the anus equal to twice the length of the tail. It 

 is possible that a pre-anal row of gland-outlets exists on the male, 

 but I could make out nothing very definite. The caudal glands 

 are three in number, and are situated, one behind another, some 

 distance in front of the anus. 



This vivacious little worm is common in Port Jackson, New 

 South Wales, Australia (1892), on marine algse and in sea-sand at 

 their base wherever the water is not foul. Its movements are of 

 the most active kind; for a time it will wriggle so rapidly as to be 

 almost invisible, then, without an instant's notice, come to a perfect 

 standstill with lightning-like rapidity, lie for some time as if dead, 

 then suddenly resume activities. It seems to be almost wholly 

 diatomivorous, and is able to swallow with ease a diatom nearly 

 half as long as its own neck and one-fourth as wide — a veritable 

 sword-swallower. The frustules of the diatoms appear never to be 

 digested. 



« Ti/r "2 5- 9- -59-^° 76- _, . . 



2. M. BREVICOLLIS, n.Sp. p 1-5 ^-q ^. jT^ 1*7 mm. ThlS IS 



a species that needs further study before its character will be 

 sufficiently known to settle its affinities. The cuticle is trans- 

 versely striated and bears short and inconspicuous hairs. The 

 neck is conoid and the head is somewhat rounded. The cephalic 

 setae are ten in number, those of each submedian pair being of 

 unequal size ; in addition there are numerous subcephalic setse, 

 prominent among them being four long and slender submedian 

 ones, situated as far behind the lateral organs as the latter are 

 behind the anterior extremity of the body. There are three pairs 

 of transparent confluent lips. The circular lateral organs are 

 one-third as wide as the neck. The simple pharynx is excessively 

 small. The cesophagus is one-half as wide as the neck and is 

 separated from the intestine by a shallow but distinct constriction. 

 The intestine, whose contents are manifestly of vegetable origin, 

 is composed of cells packed closely with granules without a 

 tessellated arrangement. The ventral excretory pore api)ears to 



