( 149 



EXPLANATION OF FIGURES. 



{For all figures.) 



a e b = anterior enteric branch. 



b = brain. 



be = bursa copulatrix. 



be = brain eyes. 



c c = central canal of the granule-gland. 



cbt p = chitinous processes of the male copulatory organ. 



con = connective tissue. 



d sh = duct of shell gland. 



e b = enteric branch. 



em = enteric mouth. 



fl = flattened epithelium. 



g g = granule-gland. 



gl cl = canals of the granule-gland. 



gl c = glandular cells of the granule-gland. 



mi = main intestine. 



mo = outer mouth. 



msc = musculature. 



ov = oviduct. 



ov d = opening of the vasa deferentia into the seminal vesicle. 



p b c = papillae of bursa copulatrix. 



ph s = pharyngeal sac. 



p n = parenchyma nuclei. 



ps = penis. 



s d = seminal duct, 



s p = spines of penis. 



s v = seminal vesicle. 



t = testes. 



t e = tentacular eyes. 



ut = opening of uterus to oviduct. 



v d = vasa deferentia. 



J = male genital opening. 



? = female genital opening. 



Plate XV. 



PIG. 



1. Longitudinal section. Enlarged ca. 5. 



2. Sketch of anatomy. 



3. Granule-gland, median longitudinal section. Obj. -3, Oc. 3. 



4. Chitinous processes round the ductus ejaculatorius. Obj. 5, Oc. 0. 



5. Spine of penis from a longitudinal section through the copulatory organ. 



Obj. 7, Oc. 3. 

 (5. Longitudinal section through the bursa copulatrix. Obi. 2, Oc. 0. 

 7. Schematic representation of the copulatory apparatus. 



