142 CAMFORNIA ACADEMY OF SCIENCES. 



ones. The gizzard is connected by several poweiiiil muscular strands with the body- 

 wall in xi. 



There is a very large mass of /)'/il')-nephridi(tl tubes situated immediately above 

 the posterior part of the pharyngeal gland. Longitudinal sections show the anterior 

 nc'ithridial canals to be greatly folded and very narrow. There are very large masses 

 ol free ca'lomic cells situated in the somites containing the sperm-sacs and the funnels 

 of the sperraducts. 



Acanthodrilus Vasliti n. sp. 

 Figs. 148-154. 



General Remarks. This species is one of those abnormal forms which occur 

 in almost every large genus, and whose organization and characteristics are not readily 

 accounted for. It is also the most nortlicin of any Acanthodrilus found so far, though 

 undoubtedly true Acanthodrili will be found much further north. Acanthodrilus 

 Vasliti differs from any other Acanthodrilus in possessing eight prostates or spermi- 

 ducal glands, ari'anged in four pairs, two and two prostates oi)ening together in each 

 one of the four prostate pores in somites xviii and xx. Also in one other respect does 

 this species show an interesting characteristic. The peritoneum lining the septa and 

 body-wall is covered with cnornions glinuhilar cells, verj' much resembling those 

 forming the nephridial mantle in many species. The duplication of the prostates is 

 also found in Ktrrin McDonnldi, while abnormal development of peritoneal cells re- 

 mind us of certain ca?lomic organs found in Periclueta and some species of Acantho- 

 drilus (Beddard, page 29, Monograph of (J)ligoth!eta). Four pairs of prostates have 

 been described by Ude in Geodrilns siiujularis, but details are wanting. 



Of the specimens in my possession one was sectioned longitudinally, two were 

 dissected and afterwards sectioned vertically. None of the specimens were fully 

 adult; the various generative organs were developed, but there was no trace of 

 clitellum. 



Hahititt. Tepic, Territory of Tepic, Mexico, at 4000 feet altitude, in the 

 moist ground immediately under decaying logs, in the shade of a stone-fence, about 

 one mile north of the city. October, 18!)4, Eisen and Yaslit, col. 



Color. Milky white, like an Ench3'trieus, without trace of pigment. 



Size. Length (> I'Ui. by 2 mm. in the region of somite viii. Slightly t<ipering 

 towards the tail, the end of which is thickened. 



Number of somitt;!^ 92 in the largest specimen, all of about the same size, ex- 

 cept the last few caudal ones, which diminish in width towards the most posterior 

 somite. All nre smooth, the anterior ones with a faint tiace of trisegmentation. 



Doisal //ores. The most anterior one that is distinct is seen l)etweeii ix-x. 

 Jietween vii/viii and viii/ix tiiere is respectively a much snialler but still distinct pore. 

 The most anterior pore is thus between vii viii. 



I'roxtomium is distinct, dividing somite i about .'.. Tlie anterior somites are 

 more distinctly .set than the others. A long narrow groove begins on the ventral 

 median line between somites xvi and xviii, and extends backwards about 20 to 25 



