PACIFIC COAST OLIGOCH ATA, 145 
generic characteristics four pairs of prostate glands, but does not describe nor figure 
these in detail. The only way I can understand the presence of four pairs of pros- 
tates opening into four pores, is that two and two prostates open together. But on 
the following page (70) we are told that there are two pairs of prostates in segments 
18 to 22, which open in segments 17 and 19. The figure shows us four prostate pores. 
If the first statement is not a misprint, we would in @eodrilus singularis have an 
analogy similar to what we find in Acanthodrilus Vasliti. But Beddard states in his 
large monograph on Oligochieta that @eodrilus singularis is probably identical with 
Diplocardia communis. This could, of course, not be the ease if the prostates were 
duplicated in the former. 
Tubercula pubertatis. Although no large and prominent elevation in the 
genital region is found, I have, however, satisfied myself that a tubereula pubertatis 
is really present even in my undeveloped specimens. Adjoining the prostate pore is 
a small tubercle, consisting of some tall supporting cells surrounding a bundle of sense 
cells, the latter characterized by the usual long, oval nuclei. These nuclei are 
situated much deeper than they are in the sense cells of the epidermis or in the buceal 
cavity, and they are also narrower than those. Otherwise this organ shows a very 
great resemblance to those in Benhamia, except for the absence of the glandular 
refractive cells. At the base of the sense cells in the tuberele I find numerous smaller 
round nuclei, the relationship of which my sections do not fully explain. Numerous 
nerve fibrils are seen to connect with the sense cells. Although no clear glandular 
cells are seen around the sense-organ in the tubercle, it may be possible that some 
may develop later at the same time as the clitellar cells, none of my specimens pos- 
sessing any. 
Vascular system. The last heart is in xi. The dorsal vessel is single; no 
subneural vessel. A large blood sinus in xvi to xix inclusive. 
Nephridia are strictly paired, opening in front of sete 3and 4. Those posterior 
to somite xiv are surrounded by large peritoneal cells, while those anterior to xv con- 
sisted of the usual narrow ducts, free of any ccelomic peritoneal cell mantle. Numer- 
ous blood vessels cover the nephridii. The most anterior nephridium is found in iii. 
No pepto-nephridium. The anterior nephridia gradually diminish in size towards the 
anterior part of the body. 
ALEODRILUS 7. gen. 
Figs. 66 to 86. 
Derinition. Acanthodrilide. Paired meganephridia, not alternating. Pros- 
tate pores, two pairs; one pair in wx and one pair in xxii. Svermiducal pair of pores 
inva. No caleiferous glands; no penial sete. Two pairs of spermathece in viii and 
ix. Olitellum wiii-ax. Two gizzards. 
General remarks. I possess only one single specimen of this interesting oli- 
gocheeta, collected at Ensenada de Todos Santos in the northern part of Baja Califor- 
nia. My time for searching was very limited and the season unfavorable, and this 
will account for the want of specimens. The single specimen was found in the dry 
