242 CALIFORNIA ACADEMY OF SCIENCES. [Proc. 3D Ser. 



The septal formula is as follows : 



IV/V, VTVI, VI/VII, VII/VIII, VIII/IX, Ix/x, X/XI, 

 XI/XII, XII/XIII, XIII/XIV. 



Intestine. — The tubular part is narrow and even and joins 

 a vascular crop in XIV. This crop is more vascular than 

 that of the species and is shorter and narrower. It is also 

 strongly contracted at the septa, which is not the case in the 

 species. 



Sperm-duct. — In a recent paper Michaelsen (30) has 

 given great importance to the assertion of A. lizuka, that 

 the sperm-duct in Pontodrilus inatsushimensis lizuka tra- 

 verses the wall of the whole glandular prostate in order to 

 enter it at its distal free end. lizuka assumes that this 

 peculiarity is a common characteristic of all species of the 

 genus. A re-examination of the type specimens of P. 

 Michaelseni, as well as a careful study of two sets of serial 

 sections of the variety in question, shows conclusively that 

 the sperm-duct enters at once and directly into the gland- 

 ular prostate at a little distance above its junction with the 

 muscular part. There is, however, a long and thick blood- 

 vessel which takes the same course as the sperm-duct 

 figured by lizuka. Michaelsen (30, p. 221, line 10), who 

 has described a variety of the Japanese species (P. masush- 

 imensis var. chatamianus) , appears to be somewhat uncer- 

 tain about the exact point of entrance of the sperm-duct. 

 Under these circumstances it seems to be premature to 

 place any great importance on the possibly aberrant struct- 

 ure of the sexual apparatus of the Japanese species. 



SpermatheccB. — The spermathec^e are much larger than 

 in the species. They occupy the largest part of their re- 

 spective somites. The form of the main sac is also differ- 

 ent from that of the species. 



Nephridia. — As in the species these organs begin in 

 somite XIII. The nephridia anterior to the clitellum are 

 furnished with only a few accessory cells, while those 



