126 Mr. C T. Regan on the Anatomy and 



to the vomer is ligamentous, the temporal fossae are apparently 

 not roofed, the upper limbs of the post-temporal are attached 

 by ligament to the epiotics, but nearly meet above tlie supra- 

 occipital, and the pelvic bones are simple triangular plates. 

 I have had no skeleton, and I have ascertained these characters 

 from examination of a spirit-specimen. The coracoids and 

 pectoral radials are intermediate between those of Aulopus or 

 Alyctophum and Bathyptei'ois. The hypocoracoid is narrowed 

 forward below, but meets the cleithrum far above the sym- 

 physis, and tiie radials are compressed, but not greatly enlarged. 

 The circumorbital and nasal bones are thin, but otiierwise 

 as in Aulopus. With Chlorophthahnus I would associate 

 a number of genera which agree with it in the following 

 characters at least : — 



Snout obtusely rounded when seen from above ; mouth 

 terminal, with the lower jaw prominent ; maxillary dilated 

 posteriorly, with a single supramaxillary usually present. 

 Pointed teeth forming narrow bands or a single series in the 

 jaws and usually on the palatines ; vomerine teeth, when 

 present, forming two well-separated patches. Dorsal fin 

 short; pectorals lateral ; pel vies usually not widely separated. 

 Skeleton rather weakly ossified ; ethmoid without median 

 keel ; post-temporals nearly meeting above the supraoccipitai. 

 No air-bladder. 



Synopsis of the Genera 0/ Sudidse. 



I. Body moderately elongate, subcylindrical ; head as broad as deep ; 



snout rather short ; maxillary reaching to below anterior part or 

 middle of eye, which is large ; pelvic tins below the dorsal. 



1. Chlorophthalmus , 



II. Body elongate, subcylindrical or compressed ; head depressed, with 



the snout more or less spatulate ; mouth large, the maxillary 

 extending beyond the eye ; pelvic fins in advance of the dorsal. 



A. None of the fin-rays prolonged. 



Eyes present, moderately large 2. £athysauroj)sis. 



No eyes ; a paired phosphorescent organ on the 

 head, covered by the thin frontal bones, to the 

 lateral edges of which the suborbitals are 

 attached 3. Ipnops. 



B. The outermost ray of the pelvic and the lowest of the caudal 



excessively prolonged ; eyes present, small. 



Pectorals normally formed 4. Benthosaums. 



Pectoral divided into two subcontiguous portions, 



the upper part 7-rayed, the first ray prolonged 



and bifid, the rest gradually decreasing in 



length below, the lower part of 5 or 6 simple 



filamentous rays 5. Hemipterois. 



C. Outermost pelvic ray usually bifid, or the two branches may 



coalesce ; if short it is thick and fiatteued distally, if prolonged 



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