folsom: mouth-parts of orchesella cincta. 31 



par un tube contourne qui, dans sa region glandulaire, se compose de 

 cellules plates a gros noyaux et a bordure striee ; le conduit excreteur, 

 plus etroit, debouche a l'extremite posterieure de la fente mediane de la 

 levre inferieure. Ces glandes, decouvertes chez Macrotoma flavescens par 

 Tullberg, qui les considerait comme glandes salivaires, ont ete figurees 

 ensuite cbez Lipura [Aphorura] ambulans par Nassonow qui les fait se 

 deverser dans la cavite buccale ; elles ont ete signalees chez Anurida 

 maritima par Fernald, qui a decouvert leur veritable role. De l'orifice 

 de la glande jusqu'au tube ventral, la secretion suit une gouttiere chi- 

 tineuse incomplete, qui court sur la ligne mediane de la face inferieure 

 de la tete et du thorax, en passant entre les pattes ; elle descend le long 

 du tube ventral pour aboutir au sillon qui separe les deux lobes de cet 



organe." 



I do not deny these observations upon Anurida and Smynthurus, espe- 

 cially in the face of Fernald's positive assertion, — I have not examined 

 those genera with reference to this question, as to do so would take me 

 beyond the scope of this paper, — but I have been unable to confirm the 

 observations in the case of Orchesella. In this species there is no com- 

 mon median duct, although the approximating sides of the labial cleft 

 might possibly be mistaken for such. I find no distinct opening through 

 the labium into the linea ventralis ; this structure is, as I have described, 

 and as Willem et Sabbe admit, " une gouttiere chitineuse incomplete," 

 being always more or less open (Plate 3, Figs. 26, 27) throughout its 

 length, and moreover becoming more or less interrupted between the 

 body segments. In short, it is doubtful if it can have the function of 

 conveying even a viscid fluid. Furthermore, the exsertile processes of 

 the ventral tube are themselves well pi'ovided with unicellular glands 

 already described by Sommer ('85), but disregarded by Willem et 

 Sabbe ('97), sufficient to furnish the viscid secretions. It is my 

 opinion, then, that the larger cephalic glands of Orchesella are truly 

 salivary glands, as are those of Macrotoma [Tomocerus] and Lipura 

 [Aphorura] in the opinion of Tullberg and Nassonow. 



The second pair of glands lie close to the skull on either side of the 

 head, between the bases of the mandible and maxilla. Each gland con- 

 sists of a somewhat conical mass of secreting cells converging downward 

 to a chitinous duct which follows the skull down, between the mandible 

 and maxilla, becoming triangular in cross section, and opens through 

 the lateral wall of the mandibular pocket, about half way down the 

 mandible. 



The glandular cells (Plate 4, Fig. 35, gl) are polygonal, with large 



