570 
structure of the arms and the bar, and the mode of connection of the 
parasite through these arrangements to the wall of the nasal chamber 
of the skate. The structure of two bulb-like protuberances from the 
sides of the ceplialo-thorax, immediately in front of the roots of the 
arms, was then described. These were the eye-like spots of Ret- 
zius and Kroyer. 
Abdomen f^ths of an inch long, T ^ths broad ; had an inverted 
heart-shaped form ; imperfectly defined segmented appearance. 
The fourth segment, the largest, possessed a median slit-like anal 
aperture, two elongated ova strings, and two posterior abdominal 
appendages. The arrangement of the intestinal canal, ovaries, and 
cement organ was then described. The authors then pointed out 
certain appearances which they considered indicative of the existence 
of a nervous system. 
The authors agreed with Milne-Edwards in thinking that the 
elongated cephalo-thorax and the posterior abdominal appendages 
point decidedly to the advisability of separating this animal from the 
genus lerneopoda. None of the specimens they examined had the 
male attached, so that they have not examined it. They have seen 
the larvae in various stages of development. When free, the larva 
was g-yth of an inch long and J^th of an inch broad ; oval when 
viewed from dorsal surface ; profile view showed a convex dorsal 
and almost flat ventral surface. It possessed a pair of antennae and 
two pairs of limbs. Each of the first pair of limbs was bifid, the 
two branches bearing long hairs at their extremity. Each of the 
second pair was bifid, the two branches bearing each a spinous hook 
at its extremity. A remarkable tail-like prolongation, fringed with 
pinnate hairs, was then described. The curved intestinal canal, the 
eye spots, and the pigment masses within the visceral chamber, were 
then adverted to. 
2. Memoir of the Life and Writings of Robert Whytt, MJX, 
Professor of Medicine in the University of Edinburgh, 
from 1747 to 1766. By William Seller,*" M.D., F.R.S.E., 
F.R.C.P.E. 
Biography, the author said, had never done sufficient justice to 
Robert Whytt, while it began already to omit his name. Whytt 
had commonly been represented as a follower of Stahl ; and this 
