164 CAUFOKNIA ACADEMY OF SCIENCES. 



towards and around a small concave pit or groove in the outer edge of the epidermis 

 (lig. 105). 



h. Interior to these taller cells are shorter and thicker cells, indicated as 6 in the 

 above figure. 



Exterior to these, the regular and characteristic tubercula pubertatis cells 

 proper are seen numerous unicellular glands, the same as the goblet cells of the 

 epidermis. 



In addition to these glandular cells, I find at certain intervals a few sense cells 

 opening out into the narrow pit or groove just referred to. They are everywhere very 

 few in number, tall, narrow, with now and then the tip projecting through the cuticle 

 into the shallow pit (fig. 105 s.c./.) There is not a contiiuious row of these cells, but 

 here and there are found bunches of half a dozen cells, opening close together. They 

 do not seem strictly parallel, but bulge and diverge in such a way that in sections, 

 which show the common cells parallel, rarely more than one single sense cell is in 

 view to any great i)art of its length. This, together with the small number of these 

 cells, is undoul)tedly the reason why they are frequently overlooked. 



In connection with these sense organ cells, I have re-examined the ventral 

 papillcE found in Ar(jilo2')h'Uas marmoratu><, and I find that these structures are really 

 nothing but tubercula pubertatis nature, or at least sense organs furnished with sense 

 cells, a descrijjtion of which will be deferred to a future paper. As a general con- 

 clusion, I may state that the tubercula pubertatis are really sense organs, furnished 

 with sense cells of the same nature as those found in other parts of the epidermis, and 

 described by me in Benhamia, and by Vejdovsky in Rhynchelmis, by Cerfontaine 

 and Langdon in Lumbricus, by Hesse in Lumbricus and Allolobophora, etc. 



Septa. The septa are not all of the same thickness, neither is each individual 

 septum of the same thickness throughout. The first distinct septum is found between 

 iv/v. It is of regulation thickness, or as thick as septum x/xi and those following 

 posteriorly. The anterior septa increase in thickness forwards and backwards in such 

 a way that septa vi/vii, vii/viii are of about equal thickness, while those in front and 

 behind these are thinner in proportion as they are more distant. The anterior five 

 septa are much thicker in their central area, and thin out towards the periphery and 

 body-wall, but even then, at the thinnest part, they are about four times thicker than 

 the posterior septa. The six anterior septa do not strictly correspond with the seg- 

 ments, but are attached to the body-wall about ()ne-fifth the distance forward from the 

 posterior intersegmental groove. 



Supraj^harijiigenl and septal glancU. The glandular mass superposed on the 

 pharynx and opening into it, is prominent, but situated far back, and with its lobes 

 pointing forward, or in the same direction as the septal glands. The opposite is gen- 

 erally the case, and has been so in all other species examined by me. 



Longitudinal sections show that the regular septal glands are present m three 

 somites. The most anterior pair is in iv, immediately behind the suprapharyngeal 

 glands, and not separated from the latter by any septum. The other two pairs are in 

 V and vi. In longitudinal sections the suprapharyngeal glands are seen to be com- 



