CALIFORNIA EUDKILID.K. 45 



regular, tlie former reseiiihling small sugar-loaves stanilhig in a row, with the tan-like 

 arranged tuhular cells between them (fig. 120). In some sections a bunch of nerve 

 fibers is seen on either side touching the pa])illa, connecting on the wther hand with 

 the ventral ganglion. As to the nature of the papilla Dr. Michitlsen suggests that a 

 somewhat similar organ in Acnntliodrilu^ (/eorf/ijtniis is a taste or " Wollust" organ. 

 It is, however, not unlikely that the minute light-refractive bodies are glandulous. 



Many of the tubular cells contain a line granulated secretion in varying quan- 

 tities, which stain dark red with cosine. The fact that the whole papilla is concave in 

 the center speaks also strongly for the glandulous nature of the organ. The figure of 

 the "Augenapfela"-like organ of Acanthodrilus, given by jNIichivlsen, may [)ossibly have 

 been taken from a young papilla in which the glandulous bodies had not yet developed. 

 Organs of a somewhat similar nature have also been described by Horst from Ponto- 

 scolex coretliruruii which, however, he does not figure in connection with nerve fibres. 

 It is not improba1)le that all the sensory organs in the genital somites of the higher Oligo- 

 clut'ta are of an analogous nature. Among such organs would be included the tuber- 

 cula pubertatis, the puberty grooves, as well as some other epidermal structures in 

 Heliodrilus, Hyperiodrilus and Eudrilus described more in detail by Beddard. How- 

 ever all the organs require re-examination by the aid of other methods, as one single 

 method of staining will not suffice to reveal their true nature. 



Svpta (fig. 86). The anterior septa are greatly pouched, generally to such 

 an extent that in cross-sections the various organs appear to lie several somites further 

 back than they really do. Thus the gizzard and the posterior spermatheca may be 

 seen in the same cross-section and this is also the case with the oviduct and the sperm- 

 sacs. This pouching is principally restricted to the septa 5 to 13. These septa are 

 also slightly thickened especially those bounding somites viii to xi. 



Neplivldhi (figs. 59 to 77). The position of the nephridio-pores places Argilo- 

 pliilus very close to Plutellus. There are one pair of nephridia in each somite as usual. 

 The first pair of nephridia are found in somite ii and others follow in all the posterior 

 somites. The first five or six nephridia are somewhat larger than the others and open 

 in front of the fourth setfe. All the following open irregularly in front either of the 

 third or fourth setse, or in the space between and anterior to them, or even outside of, 

 or more lateral than seta four. Those which open laterally of seta four do not even 

 open in the same row, as we find one nephridio-pore say as far out laterally from 

 the fourth seta, as that seta is distant from the third, while others are half-way or one- 

 third of the way between the fourth seta and the most lateral nephridio-pore. There 

 is no regularity as regards this succession, though rarely two successive nephridia open 

 in line behind each other. For instance, one nepliridium opens in front of seta 

 3; the second as far outside of 4 as 4 is distant from 3; the third nephridio-pore is 

 in front of seta 4, the following half-way between seta 4 and the most lateral pore, 

 the following § of the distance from seta 4 to the most lateral pore, the following in 

 front of seta 4, the following again § of the distance from seta 4 to the most lateral 

 nephidio-pore, etc. (Fig- VIA np. ji.) 



Memoies, Vol. II, 3. January, ISW. 



