NEW MALLOrHAGA. 



209 



posterior end of the last abdominal segment forward into 

 the fifth. (Grosse states that this is the turned-in tenth 

 segment of the male. Heyond the fact that tiie male 

 has one segment less in the abdomen than the female, 

 he gives no evidence for this conclusion). The cavity 

 thus formed corresponds exactly with the genital cham- 

 ber of other species. Into the posterior part of it the 

 rectum opens from above. Its anterior end is evag- 

 inated, and the tube thus formed is homologous with 

 the membranous penis of other forms. It is almost 

 destitute of chitinization, however; the rod arising in 

 other species from the base of the penis is here situated 

 near the ti{). It appears from this that the elongation 

 of the parts has been brought al.iout, not by a deepening 

 of the genital cavity with a corresponding lengthening 

 of the penis iu a posterior direction, but by a deepening 

 of the genital cavity with a lengthening of the penis iu 

 front of its base. The innermost tube is produced by 

 an invagination of the posterior end of the penis and is 

 either unrepresented in other forms or is comparatively 

 extremely short. Figure 9 represents diagramnuvtically 



Fig. 9 — PiaRram of Iiilroniitteut orttan of Mmo/ton titin, male: a, anus; gc, Renilal 

 cbatnber; g, ejaculutorj- duct; p, peuis; f], luuormosi Invagiuated tul>e; t<, uiltliUe 

 invaglnaled tube; (3, outennoBt Invagiuatod tube or wall of genital cbaiuber ^ cf. 

 tig. 5). 



the relation of the several tubes, and a comparison of 

 this figure with lig. 5 shows the similarity of strueture. 

 (cf. also plate xv, tig. "2 with fig. 1). 

 1-1 



