On the Pineal Eye of the Porbeagle Shark. 67 
EXPLANATION OF PLATE. 
Fig. 1. Longitudinal vertical section (x50), through pineal region of 
Lamna cornubica. ¢., cartilage in process of development; c¢.c., central 
canal or lumen of pineal stalk ; ¢.c.¢., clear (almost transparent) connective 
tissue ; ¢.¢.s., connective tissue sheath of pineal body; c.t.s’., connective 
tissue sheath of pineal stalk; £.c.t., ordinary embryonic connective tissue, 
with innumerable connective tissue corpuscles ; Ep., superficial epidermis ; 
P.B., pineal body ; P.P., pineal pit, or involution of the epidermis ; P. St., 
pineal stalk ; p.v., pineal vesicle, the letters are situated in the cavity of the 
vesicle ; s.y., secondary involution of the epidermis, 
Fig. 2. Zp., small portion of epidermis of pineal pit, more highly magni- 
fied ( x 300) ; m.c., mucous cells, 
VII. Some Further Notes on the Summer Birds of Shetland. 
By Haro_p Rarpury, Esq. 
(Read 18th March 1891.) 
The following notes consist of a few additions to, and 
corrections on, a paper published in the Proceedings of 
this Society for 1888 (vol. ix., p. 542). The numbers refer 
to the figures opposite each species in that paper, and the 
additions to the list are given higher numbers. 
3. Merlin (Falco esalon).—A nest, found 12th June 1890 
in Sandsting, contained four young birds a few daysold. As 
in 1887, this was a “sham” nest—a nest of the hooded crow, 
begun and given up for some reason—placed on a rocky slope. 
The old birds were very bold, the female coming sweeping 
past my head within a yard or two—always, however, from 
behind—with almost invisible speed. A hand raised had the 
effect of instantly causing her to shoot up many yards in 
the air. 
14. Snow Bunting (Plectrophanes nivalis)—A nest of this 
bird is said to have been obtained in Yell a few years ago, 
and this is given as a locality by Howard Saunders in his 
recent “ Manual of British Birds.” 
23. Swallow (Hirundo rustica).—While at Melby on 13th 
June 1890, I was informed that, about three weeks previous 
to my visit, a number of swallows had been seen frequenting 
the locality for some days. None remained to nest, however. 
26, Red Grouse (Lagopus Scoticus),—There are a few grouse 
