160 CALIFORNIA ACADEMY OF SCIENCES. 



and xiii there are no connecting vessels. In xiv to xvii we find the dorsal vessel en- 

 larged and folded on itself in a zigzag manner. Both hearts and dorsal vessels are 

 thickly covered with chloragogen cells. I have already pointed out the absence of 

 a continuous blood sinus in any of the various parts of the intestine. All the various 

 organs of the body are thickly covered with blood capillaries, especially so the neph- 

 ridia, spermathecoe, the clitellura, in which strong capillaries separate every two or 

 three rows of the large clitellar cells. Tn the center of the tubercula pubertatis is 

 always seen a dense mass of larger and smaller capillaries. 



A characteristic of the vascular system is also the great scarcity of blood 

 glands, these being very numerous in Sj). Benhami. 



Sparganophilus sonomae n. subsp. 

 Figs. 123, 126. 



Habitat. Creeks and springs around Sebastopol, Sonoma County, California. 

 Adult specimens very numerous in April. 



General Remarka. I consider SparganopTiihis sonnrnre as probably a sub- 

 species under Sp. tSniUhi, which it resembles in most points, two of which are of 

 the greatest importance, viz.: The jiosition of the spermduct and sperniiducal pore, 

 and the duplication of the spermathecie in several somites. But as long as I found 

 the number of spermathecse constant, and some other minor points of difference, I 

 thought it best to describe this form more carefully, leaving the question of species or 

 subspecies as a matter of choice, and for future consideration and study. 



EXTERNAL CHARACTERS. 



Tubercula pubertatis are the only external organs which differ from Sp. Smithi. 

 While in Sj)- iSmithithey form a continuous ridge on either side, they are in Sp. sonovim 

 broken up in numerous tubercles, generally two or three on each somite (fig. 123). 

 I believe there is another characteristic worthy of mentioning. The single puberty 

 groove is in the center of the tubercle, while in Sp. Smithi there are two grooves, one 

 at the base on either side of the tubercle. But I freely confess that I have not sec- 

 tioned up a sufficient number of specimens in order to know if these points are really 

 constant, or if not rather they are subject to considerable variation. My supply of 

 mature specimens of Sp. sonomte was very limited, but in all I found the tubercula 

 pubertatis l)njken into a succession of little knobs, but all together forming a ridge 

 in outline like that of Sp. Smithi. 



INTERIOR CHARACTERS. 



Spermathecce. While in all the specimens of Sp. Smithi I found eight sperma- 

 thecfe in each of somites vii, viii, ix, the subspecies possess them as follows: Somite 

 vi: one pair with the pore in front of seta 4. Sojiiites vii, viii, ix: two pairs (4) in 

 each, with pores in front of settle 4, and between 3 and 4. Each pair consists of two 

 separate spermathecae, one of which opens in the intersegmental groove in front of 

 seta 4, while the other opens similarly in front of a line drawn | the distance between 

 setfe 3 and 4, the ^ being towards 4 and the § towards 3. Both pairs are, therefore. 



