PACIFIC COAST OLIGOCHiETA. 159 



athecfe varied some, but the general shape appeared quite constant within certain 

 limits. The figures appended represent the spermathecte taken from one specimen. 

 There is a narrower muscular basal tube and a more swollen non-muscular chamber 

 as usual, the structure of wliich offers no characteristics. 



Sperm-sacs. Of the two pairs of sperm-sacs the anterior one in somite xi is 

 much the narrowest in the direction of the median longitudinal diameter of the body. 

 It is principally ventral in location, but extends upwards and joins the one from the 

 opposite site. It is closely surrounded by a sperm reservoir without enclosing mem- 

 brane. Tlie sperm-sacs in xii are much broader and longer, but are generally only 

 dorsal and do not enclose the intestine in any of the specimens sectioned. This rela- 

 tive size of the two pairs of sperm-sacs appeared constant. Somites ix and x are 

 transformed into two very extended sperm reservoirs. 



Ovaries in the various species are long and flat, not lobed, an<l in both longitu- 

 dinal and transverse section offer to view a single undivided surface. 



Oviducts are very broad and furnished each with an ovisac consisting of an in- 

 vagination of the septum, which in all my specimens were filled with large gregariuiie, 

 rarely containing any ova. 



C iliated rosettes are s'umhdv to those ol Sp.'Benhami'xw si/.e. The spermducts run 

 ventrally to as the tubercula pubertatis, aliout four times as far laterally and dorsally 

 from seta 2, as 2 is distant from seta 1. The spermiducal i)ore is similarly situated 

 ventrally to the tubercula pubertatis, This characteristic is in all the species only 

 shared by SparyaiiophHas soaom'e. All other species are characterized by having the 

 spermducts run dorsally as to the tubercula pubertatis. The si^ermiducal pore is simi- 

 larly in Sp. Smithi situated ventrally to the tubercula pubertatis, and is found in the 

 intersegmental groove between somites xix/xx. 



Prostates or spermiducal glands (Beddard). There are three pairs of spermi- 

 ducal glands, one pair each in somites xxii, xxiii, xxiv. One specimen possessed only 

 one gland in xxiv, and there may possibly be found some variation in number when 

 more specimens have been investigated. In all cases these glands were much smaller 

 than in SparganophUus Benhaml, but otherwise almost similar in structure, except for 

 the entire absence of the basal muscular duct. The glandular part was never large 

 enough to be folded on itself lengthwise, but its tube was much twisted in the direction 

 of its long diameter, often to such extent that cross-sections always showed the tube 

 as three or four circular openings, surrounded by a wall two cells thick. The muscu- 

 lar basal part is absent, and the lower tube, where it enters the muscular layers, being 

 very short, is surrounded by a thin layer of connective tissue. The whole organ in 

 mature specimens projects only slightly above the body-wall, and the glandular part 

 is in either diameter not any thicker than the body-wall. 



Nephridia are in this species covered and perforated by numerous blood 

 capillaries, to a much greater number than in Sparc/a uophUus Benhami, but .similar to 

 what is described in Sp. tamesis and Sp. Eiseni. Otherwise the nephridia of the re- 

 spective species appear to be of the same general size and .structure. 



Vascular system. The hearts begin in xi, and extend forwards to viii. In xii 



