162 
ZOOLOGICAL LITERATURE. 
^by a gradual, partial rotation of the front part of the skull 
I round its longitudinal axis. Not only can it be demonstrated 
\ from an analysis of the head of an adult fish, that the position 
j of the upper eye in relation to the frontal bones of the blind 
I side is not e:^plained by a simple rotation of the head, but the 
s young specimens mentioned show that the eye of the blind side 
passes to the eye side, piercing the tissues befow the arch formed 
i by the frontal bones of its own side, separating them from the 
I frontals of the other side, and taking its position above the 
I other eye. — Specimens showing the upper eye situated in the 
j median line of the ujoper surface of the frontal arch are mon- 
■ strosities, and therefore they cannot prove the correctness of 
■ Van Beneden^s theory. Thus, the specimen described by Hr. 
I Malm as the young of Rhombus laevis is nothing but a mon- 
I strosity, like Honovan^s Pleuronectes cyclops. Of particular 
interest is Hippoglossus pinguis (Fabr.), which reminds us of 
those Cyclops-monstrosities in having both sides equally de- 
veloped as regards muscles as well as coloration, and in having 
the upper eye situated on the top of the snout. Future researches 
! must show whether this is really a monstrosity of some other 
I species. — ^This excellent memoir is illustrated by several wood- 
f cuts and by a plate showing the different stages of the metamor- 
I phosis of the young Plagusia.^^ OEfvers. Dansk. Vidensk. Selsk. 
I Forliandl. in 1863, p. 253. 
According to Hr. Malmgren the following species occur on the Finnish 
coasts : JRhombm maximus, Pleuronectes flesusj .PL dvinensis, PI. Itmanda, FI. 
limandoides, and Hippoglossus vulgaris. Wiegm. Arch. 1864, p. 293. 
Hippoglossus pinguis. Mr. Gill points out the differences between this lish 
and Pleuronectes cynoglossus. , Proc. Acad. Nat. Sc. Philad. 1864, p. 218. 
Compare Prof. Steenstrup’s remarks on this species recorded above, which 
leave no doubt that Mr. Gill is correct in considering the two fish as widely 
different. 
V Citharichthys mia'ostomus, sp. n.. Gill, Proc. Acad. Nat. Sc. Philad. 1864, 
p. 223, from the Atlantic coasts of North America. 
V {Citharichthys) Metoponops coopet i^ g. and sp. n., Gill, Proc. Acad. Nat. Sc. 
Philad. 1864, p. 198, from California. 
^ He?nirhombus ovalis, sp. n., Giinther, Proc. Zool. Soc. 1864, p. 164, from the 
Pacific coast of Panama. 
Pseudorhombus. Mr. Gill states that Platessa ocellaris and PI. oblonga of 
Dekay are identical and ought to be named Chcenopsetta ocellaris, and that 
Platessa quadrocellata (Storer) is identical with Pleuronectes oblonga (Mitch.), 
forming a species distinct from the former — Chcenopsetta oblonga. Proc. Acad. 
Nat. Sc. Philad. 1864, p. 218. 
Pleuronectes digrammus (Gthr.). Mr. Gill identifies this species with Paro- 
phrys vetulus (Girard), Proc. Acad. Nat. Sc. Philad. 1864, p. 196. We must add 
the following remarks on this point: — If Mr. Gill’s identification bo correct, 
Parophrys cannot remain as generic designation for that group of Pleuronectoids 
