Introduction.
The mail-cheeked fishes, first grouped together by Cuvier and Valenciennes (’29), are said to
be all characterized by the presence of a suborbital stay, th a t stay being formed by the extension across
the cheek, toward or to the operculum, of the third infraorbital bone. In other respects certain families
of th e group differ greatly from the others, so much so th a t they have frequently, since Cuvier’s time,
been widely separated in classificatory schemes. Modern tendency is however to bring the several
families together again, Boulenger (’04), the most recent writer on the subject, placing them all in a
single division of the Acanthopterygii, which he calls the Scleroparei. Preceding Boulenger, Gill (’88),
and, following him, Jordan and Evermann (’98), keep the several families of the group together, b u t
separate them into two suborders, the Loricati and the Craniomi. The la tte r fishes are said b y these
authors to be derived from the former and to be distinguished from them, essentially, by th e following
features only: 1. by the abnormal character of the scapular arch; 2. in th a t the post-temporal (suprascapular)
forms an integral p a rt of the cranium; and 3. th a t the postero-temporal (supraclavicular)
is „crowded out of place by the side of the proscapula above or a t the edge of the post-temporal“ .
Of th e numerous fishes of the group I have had specimens of the following species, and they
have all been more or less carefully examined in connection with the present work:
Scorpaena scrofa, S. porcus,
Sebastes dactylopterus,
Cottus octodecimospinosus, C. scorpius,
Trigla hirundo, T. gurnardus, T. lyra, T. pini, T. lineata, T. obscura,
Lepidotrigla aspera,
Peristedion cataphractum, and
Dactylopterus volitans.
The three specimens of Cottus octodecimospinosus and the two specimens of Trigla gurnardus
th a t I have had, were kindly sent me, respectively, by the U. S. Fish Commission Station a t Wood’s
Holl, Mass., and by Dr. Allen of the Plymouth Biological Station, England. Of Cottus scorpius I have
had only a few embryos and larvae kindly sent me by Prof. W. C. Me. Intosh of St. Andrews, Scotland.
Of Dactylopterus volitans one of the several specimens was obtained from the Naples Zoological
Station. The other specimens used in the investigation were all found in the market here (Menton)
or a t Nice, and, although they are all M editerranean species, I have not always been able to satisfactorily
identify them; for the features given by Gunther (’60) as of specific value are often v ery variable,
and there are apparently, in many of those features, an almost perfect series of intermediate types.
Zoologica. Heft 57. 1