1899-1900.] Mr Crawford on Rectal Gland of Masmobranchs. 61 
DESCRIPTION OF PLATE. 
Fig. 1. — Trans, section, rectal gland of skate. x Leitz object. 
No. 3. a, lumen ; b , blood sinuses ; c, ducts ; d , Secreting Tubules. 
Fig. 2. — The same. x Leitz oil - immersion, to show 
Epithelium lining Secreting Tubules. High power view of gland 
acini. 
