Some New or Little Known Oligocheeta. 37 
IIT. Pontodrilus hesperidum, n. sp. 
The large and important family Cryptodrilidz has, so far 
as we know at present, very few representatives in the New 
World. Besides several species of Ocnerodrilus and Micro- 
scolexz, the former of which is certainly, the latter probably, 
indigenous to that part of the world, the following species only 
have been recorded from America and the West Indies :— 
Cryptodrilus spatulifer, Mich., Chili. 
Gordiodrilus dominicensis, F. KE. B. Dominica. 
Plutellus heteroporus, Perr. Pennsylvania. 
Ps perriert, Benh. British Columbia. 
Pontodrilus arenae, Mich. (=P. bermudensis, F. E. B.). Ber- 
mudas. 
I have therefore less hesitation in giving a somewhat 
imperfect description of a new species from Jamaica, which 
is certainly not identical with any of the above. The single 
specimen which I had at my disposal is immature. 
The single specimen of this worm was of small size, an 
inch or so in length, and not more than 1°5 mm. in diameter. 
The specimen being immature, there was no clitellum visible. 
The setw are paired, but the individual sete of each pair 
are at some distance from each other. On the xviiith 
segment the outermost of the two ventral sets is absent, its 
place being occupied by the male reproductive pores. The 
oviducts opén a little to the inside of the ventral sete on 
each side. 
Considering the small size of the worm, the thickness of 
some of the anterior septa is not a little remarkable. The 
present species is hardly larger than Rhododrilus parkert, 
but those septa that are thickened are enormously more so. 
It must be recollected, however, that the present is apparently 
purely terrestrial in habit, and it cannot be doubted that there 
is some relation between the thickness of the septa and the 
terrestrial habit. There are eight thickened septa, the last of 
which divide segments xii./xiii. Of these the 5th, 6th, and 
7th are decidedly stouter than the rest. There is one 
delicate septum in front of the first thickened septum, which 
therefore bounds segments iv./v. The middle septa of the 
