a 
390 MEMOIRS OF THE CARNEGIE MUSEUM 
introduction essentially unchanged until modern times. In the opinion of Dr. Gill, 
its nearest allies in the existing fauna are to be found in Antennarius itself and 
Pterophryne. 
55. Histionotophorus bassani (Zigno). 
1887. Histiocephalus bassani A. de Zigno, Mem. R. Istit. Veneto, XXIII, p. 31, 
figs OF 
1904. Histionotophorus bassani C. R. Eastman, Bull. Mus. Comp. Zool., XLVI, 
p. 32, pl. 1, figs. 1-3, text fig. ¢. 
1904. Histionotophorus bassani T. Gill, Science, n. 8., p. 845. 
Besides the type and three well-preserved specimens that are now the property 
of the Museum of Comparative Zoology at Cambridge, Mass., but one other repre- 
sentative of this species is known. It is a small form in the Bayet Collection of 
the Carnegie Museum, cataloged as No. 5237. 
Suborder PLECTOGNATHI. 
This is a highly aberrant group, closely connected with the Acanthopterygit 
through the Acanthuride, as pointed out long ago by Dareste (Ann. Sci. Nat. Zool. 
(3), xiv, 1850, p. 105). These fishes have usually been arranged in three divisions: 
Sclerodermi, Ostracodermi, and Gymnodontes, but Mr. C. T. Regan has shown reasons 
for combining the second of these with the first and third. Following is Boulenger’s 
diagnosis of the latter of these divisions: 
Division GYMNODONTES. 
“Supraclavicle oblique, sometimes nearly horizontal; lower three pectoral 
pterygials enlarged and immovably united to the coraco-scapular cartilage, upper 
pterygial small, suturally united to the scapula. Anterior vertebra with bifid 
divergent neural spines. Basis cranii simple; suture between dentary and articular 
elements evident. Pelvis absent.” 
The above definition of this group is further characterized by the same author 
as follows: ‘‘The spinous dorsal and the ventral fins are constantly absent, the 
premaxillaries are united to the maxillaries, and the teeth are coalescent, forming a 
beak; parapophyses are not developed, and epipleurals are absent. 
Family DioponTipm. 
Beak without median suture. Interoperculum rod-like, attached posteriorly 
to the rod-like anterior limb of the suboperculum. Gills 3. All the precaudal 
vertebrae with bifid neural spines. Skin with movable spines; vertebra 21 or 22. 
