SPINNING- GLANDS IN PHEYNFS. 273 



The " penis " is a paired structure, the tips of its two limbs 

 project backwards from beneath the genital operculum. The 

 general character of these limbs can be gathered from the figures. 

 They distinctly belong to the genital operculum, being out- 

 growths from its posterior wall, as shown in the diagrammatic 

 longitudinal section (PI. VIII. fig. 6). Anteriorly (or ventrally) 

 they are attached almost immediately to the fold of the oper- 

 culum, which has itself a distinct median suture. Posteriorly 

 (or dorsally) the " penis " is attached far up to the opercular 

 fold. 



The genital aperture, opening on the posterior face of the 

 operculum, is found in the channel formed by these limbs, so 

 that the genital products can be conducted backwards to between 

 the tips of the limbs, which tips are soft-skinned, somewhat 

 spoon-like processes covered with fine hairs. The floor of the 

 channel is continued to the posterior end of the limbs by a 

 membrane joining the two longitudinally {cf. figs. 2-5). The 

 structure so far seems to be an instrument for placing the genital 

 products, i. e. either a penis for the placing of the spermato- 

 phores, or an ovipositor. 



The study of these specimens further showed that this so- 

 called "penis" functions not only as a genital organ, but also 

 as a pair of spinning-mamillae for the formation of the cocoon. 



The secretion for the formation of the cocoons appears to 

 exude on the anterior (ventral) side of the horizontal uniting 

 membrane, from somewhere in the inner angles at the bases of 

 the soft tips of the limbs. I was unable to find the exact 

 apertures, but conclude that the secretion does exude from this 

 spot from the fact that in the specimen examined a fragment of 

 a membranous network made of clear, hard, thick irregular 

 threads, with apparently open meshes, still remains tightly 

 clutched by the " penis " (as shown in fig. 1). And further, 

 among the torn and disorganized muscles of the excised " penis," 

 a gelatinous mass, evidently one of the glands, persisted in situ, 

 somewhat as shown in fig. 2. The gland belonging to the right 

 side had been torn away in the process of excision. 



The delicate tips of the organ, when not in use, are protected 

 under the anterior edge of the sternite of the third abdominal 

 segment (fig. 6). This figure [since confirmed by new sections] 

 also illustrates the position of the spinning-gland. 



21* 



