142 CALIFORNIA ACADEMY OF SCIENCES. 



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

 wall in xi. 



There is a very large mass of i^epto-nephridinl tubes situated immediately above 

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

 nephridial canals to be greatly folded and very nari'ow. There are very large masses 

 of free coelomic cells situated in the somites containing the sperm-sacs and the funnels 

 of the spermducts. 



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 northern of any Acanthodrilus found so far, though 

 undoubtedly true Acanthodrili will be found much further north. Acanthodrilus 

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

 ducal glands, arranged in four pairs, two and two prostates opening 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 enormous glandular cells, very much resembling those 

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

 also found in Kerria McDonaldi, while abnormal development of peritoneal cells re- 

 mind us of certain cceloraic organs found in Perichpeta and some species of Acantho- 

 drilus (Beddard, page 29, Monograph of Oligotha?ta). Four pairs of prostates have 

 been described by Ude in Geodrilus singularis, 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. 



Habitat. 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, 1894, Eisen and Vaslit, col. 



Color. Milky white, like an Enchytrasus, without trace of pigment. 



Size. Length 6 cm. by 2 mm. in the region of somite viii. Slightly tapering 

 towards the tail, the end of which is thickened. 



Number of somites 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 are smooth, the anterior ones with a faint trace of trisegmentation. 



Dorsal ixjres. The most anterior one that is distinct is seen between ix-x. 

 Between vii/viii and viii/ix there is respectively a much smaller but still distinct pore. 

 The most anterior pore is thus between vii/viii. 



Prostomium is distinct, dividing somite i about |. Tlie anterior somites are 

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

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



