13(5 



CEYLON PEARL OYSTER REPORT. 



EXPLANATION OF PLATE. 



Fig. 1. 



3. 



4. 



5. 



6. 



7. 

 8. 

 9. 



Tart of a transverse section across the body of Wbodwmihia insigms. Epidermis and gut shown 

 quite diagrammatically. The section is in the plane AB, shown in fig. 9, and the part drawn 

 shows the median organs and those a little to the right of the middle line. 



Thal-amoplana herdmani, sketch of the appearance of the entire animal, showing the colour 

 pattern. x 4 diam. 



Dorsal eye-spots of the same. 



Section across the hinder end of the antrum masculinum of the same, in the plane marked AB in 

 fig. 8. The epidermis and body-wall muscles are shown diagrammatically. The two glands 

 (pr.gl.) are secreting actively and contain a finely granular secreted substance. 



Section across three prostatic glands of the same more highly magnified. These glands are 

 exhausted and show only the protoplasmic reticulum. 



Eye-spots of Leptoplana gardineri. 



Diagram of genital duets of Sttjhchoccsius gracilis, n. gen. and sp. 



Diagram of genital ducts of Thalamoplana herdmani, n. gen. and sp. 



Diagram of genital ducts of Woodvxnihia insignis, n. gen. and sp. 



Explanation of Lettering. 



a./., antrum femininum. 



a.gl., aperture of prostatic gland. 



a.m., antrum masculinum. 



acc.ves., accessory vesicle. 



b.ra., basement membrane. 



c.il., common uterine duct. 



c.l., circular muscle layer. 



(/.'., ductus ejaculatorius (vesicular duct). 



<?./., diagonal muscle layer. 



c.L, external longitudinal muscle layer (ventral). 



ep., epidermis. 



g., gut. 



?'./., inner longitudinal muscle layer. 



/., lobes of accessory vesicle. 



m.pr., muscular projection from antrum. 



n., nervous tissue. 

 pe., penis. 

 pi., pigment. 

 pr., prostate. 

 pr.gl., prostatic gland. 

 sh.gl., shell gland. 

 /;.;//., dorsiventral muscles. 

 yl., uteii. 



v.s., vesicula serninalis. 

 v.d., vas deferens. 

 ra., vagina. 



va 2 ., accessory part of vagina. 

 x., dark body in the accessory vesicle sur- 

 rounded by gelatinous substance. 



