74 CALIFORNIA ACADEMY OF SCIENCES. 



External po7'es. There are no dorsal pores. The spermathecal pores are 

 found between somites vii/viii and viii/ix iu front of seta 2, each one situated on a 

 slightly elevated cushion. The ovipore in xiv in front of seta 1. The male pores are 

 in xviii in front of and in line with seta 2 (fig. 26 S ). The nephropores are in front 

 of seta 2. 



Setre. The setoe commence in somite ii, eight in each segment and in couples. 

 The distance between 3 and 4 is only slightly larger than that between 1 and 2. The 

 distance between 1 and 1 is nearly twice as large as that between 1 and 2, and the 

 distance between 2 and 3 is a little smaller than that between 1 and 1 (fig. 27). 



Color of body pale flesh, rather transparent and marbled very much like 

 Deltania. Clitellum yellowish. 



INTERNAL ANATOMY. 



Body-vmll. The body-wall appears to me to be of unusual thinness, throughout 

 the length of the body. The dorsal side is slightly thinner than the ventral side, at 

 least anterior to the clitellum (fig. 29). Dorsally the longitudinal muscular layer is 

 of about the same thickness as the transverse layer while on the ventral side the 

 longitudinal muscular layer is about twice as thick as the tranverse muscular layer. 

 This refers to the anterior somites. To this there is however an exception in somites 

 viii and ix where on the ventral side in the vicinity of the spermathecal pores the 

 transverse layer is thicker than the longitudinal layer. The transverse layer tapers 

 down towards the spermathecal pores, but this thickening is found only in the imme- 

 diate vicinity of the spermatheca. In the clitellar somites the relative development of 

 the muscular layer is very different. Here the inner or longitudinal muscular layer 

 is enormously thickened laterally in somites xvii and xviii or in the vicinity of the 

 male pores (figs. 37, 38, 40, 41), while in the anterior part of the clitellum the longi- 

 tudinal layer is only thickened ventrally, between the inner couples of sette it here 

 being at least twice as wide as it is dorsally (fig. 39). 



ditellum offers many points of interest. It has already been stated that this 

 organ is incomplete, that is, not simultaneously developed on the dorsal and ventral 

 sides. A section through an immature specimen shows (fig. 38) that the clitellar 

 glandular layer is developed only between the seta, that is, from seta 4 ventrally to 

 seta 4, while donsally there is no trace of such cells. As regards the nature of these 

 cells it is to be remarked that they are unusually small or rather thin compared to the 

 larger and thicker cells of the dorsal part of the clitellum in the anterior .somites of 

 that organ. These latter cells offer nothing in particular of interest, resembling those 

 of other genera of the family as far as I can make out. Unfortunately most of the 

 specimens were immature and only two possessed clitellum, but these two had unavoid- 

 ably not been treated, and had contracted to such very great extent that the finer 

 structure of the clitellum had been hopelessly lost. From ci"0ss and longitudinal sec- 

 tions made it was, however, evident that the clitellar glandular cells, which constitute the 

 clitellum, do not extend ventrally further than to setae 1, thus leaving the ventral space 



