256 SPOLIA ZEYLANICA. 



distal prong of the fork is twice as long as the proximal, but only 

 two-thirds as broad at its base ; the nodulus is markedly proximal 

 to the middle of the length of the shaft (proximal : distal : : 34 : 50 

 or 34 : 42). Behind segment V. the ventral setse (fig. 5c) are four 

 per bundle, except posteriorly, where bundles of three and then of 

 two setse occur ; the prongs of the fork are equal in length, the 

 distal prong however is only half as thick as the proximal ; the 

 nodulus is markedly distal to the middle of the shaft (proximal : 

 distal : : 40 : 28 or 42 : 26). In length they are shorter than the 

 setse of the most anterior segments (68 jx) ; the proximal curve of the 

 shaft is ample, and better marked than in the anterior setse ; but I 

 could not discover any considerable difference in thickness between 

 the two groups. 



The buccal cavity is tubular, and extends through segments I. and 

 II. ; the pharynx, in segments III.-IV., is lined by elongated 

 columnar ciUated epithelium, the cells being specially long in the 

 dorsal wall ; the musculature of the pharynx is weak, and there is 

 nothing to suggest that the pharynx is protrusible, or that it can act 

 as a sucker, as in ^. tonkinensis ( 9, 10). Septal glands are present 

 in segments IV. and V., situated laterally and dorsolaterally on the 

 alimentary canal ; they are attached to the front faces of septa 4/5 

 and 5/6, and consist of aggregates of large ovoid or pyriform cells ; 

 a few such cells are also seen in segment VI. The oesophagus extends 

 through segments V.-VIIL, when the tube dilates to become the 

 intestine ; there is thus no stomach. Chloragogen cells begin in 

 segment VI. 



The dorsal vessel has a ventro -lateral position to the left of the 

 middle line throughout the greater part of its extent. It becomes 

 lateral in segment VII., and dorsal in VI., according to the evidence 

 of sections. The lateral commissures could not be made out. 



In asexual reproduction n = 22 (three instances). None of the 

 specimens showed any trace of sexual organs. 



In 1905 Michaelsen (7) published the following provisional diag 

 nosis of a species of Aulophorus collected by Stuhlmann m 1888 in 

 Zanzibar, reserving all description of the animal till later : " Lange 

 etwa 9 mm., Dicke max. "3 mm., Segmentzahl etwa 50. Dorsale 

 Borstenbiindel am 5 Segment beginnend, mit Haarborsten und 

 gabelspitzigen Hakenborsten. Kiemennapf mit 4 (5 ?) Paar finger- 

 formigen Kiemen. Palpen schlank, am Hinter- (Unter-) Rande 

 entspringend." 



No further account has however appeared ; and it must therefore 

 remain somewhat doubtful whether my identification of the present 

 species with it is correct. The agreement is fairly close ; I dp not 

 regard the difference in length as of great importance. I might add 

 that I saw no reason, from an examination of the limited number of 

 specimens at my disposal, to suppose that more than four pairs of 

 gills were ever present ; and that I am in some doubt as to how far 



