PACIFIC COAST Or,IGOCH.1<:TA. 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 jiage (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 Geodrilus singularis have an 

 analogy similar to what we find in Acanthodrilus Vasliti. But Beddard states in his 

 large monograph on OlignchiPta that Geodrihi.n sinf/ulnris is probably identical with 

 Diplocnrdia commun'Di. This could, of course, not be the case if the prostates were 

 duplicated in the former. 



luhercnla puhertatis. Although no large and prominent elevation in the 

 genital region is found, I have, however, satisfied myself that a tubercula pubertatis 

 is reallv 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 buccal 

 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 tubercle 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 setie 3 and 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 coelomic peritoneal cell mantle. Numer- 

 ous blood vessels cover the nephridii. The most anterior nephridiura is found in iii. 

 No pepto-nephridium. The anterior nephridia gradually diminish in size towards the 

 anterior part of the body. 



ALEODRILUS n. gen. 

 Figs. 66 to 86. 



Definition. Acanihodrilidre. Paired meganephridia, not alternating. Pros- 

 tate pores, two pail's; one ixdr in xx and one jiair in xxii. Svermiducal jJai'' of pores 

 in xxi. A"o calciferous glands; no jjenial setre. Tivo pairs of spermatheciri in viii and 

 ix. Clitellum xiii-xx. Two gizzards. 



General remarks. I possess only one single specimen of this interesting oli- 

 gochseta, 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 



