and some others, and in the spine bearing operculum of Malacanthus.  The latter genus is, moreover, described by M. Agassiz as possessing scales with toothed edges, and rough to the touch when the finger is drawn forwards.  It has the simple intestinal canal without caeca, which is proper to the Labridae.  The intestine of Pseudochromis is similarly formed, the stomach being continuous with the rest of the alimentary canal, and not distinguished by any cul de sac.  Having but one specimen of Assiculus for examination, I have not been able to submit it to dissection to see whether the structure of its intestines be the same or not, but both it and Pseudochromis differ very widely from the labroid type in their scales, possessing the peculiar firm, shining, strongly ciliated structure, which we observe in Glyphisodon and its allies, and in the lateral line being interrupted in a precisely similar manner.  Chromis and Plesiops have already been removed by M. Valenciennes from the Labridae to the Glyphisodontidae, and it is with them that we feel inclined to range Assiculus and Pseudochromis, notwithstanding the discrepancies in the form of the intestinal canal.  We can, however, trace a gradation in the variation of form.  The normal number of caeca in the Glyphysodontidae is three.  In Chromis there are generally two small ones, while the Bolti of the Nile, or the Chromis niloticus of Cuvier, has no pyloric caecum, but a large cul de sac to the stomach.  Malacanthus is widely separated from the Glyphisodontidae by its continuous lateral line.  Since these remarks were written I have seen Muller’s paper, entitled, Beitrage zur Kentniss der naturlichen Familien der Fische, in which the Chromidae are indicated as a distinct family from the Glyphisodontidae, which latter he names Labroidei stenoidei; and Pseudochromis, it is stated, belongs to neither of these families, because it has twofold pharyngeals with a division between them.  Dr. Muller promises a separate article on Pseudochromis, which I have not yet seen.

...

Assiculus punctatus.

RADII.  BR. 6; D. 3 :  23; A. 3 :  12; C. 21; P. 18:  V. 1, 5.

FISHES.  PLATE 2.  Figures 1, 2, 3, 4, and 5.

This fish is as thin in the body as a lath, whence the generic name.  Its greatest width is at the cheek, as shown by the section figure 3, where the transverse diameter is about half the height.  Figure 4 shows the section at the gill cover, and third dorsal spine, where the thickness is less; and figure 5, represents a section behind the ventrals, where the thickness is little more than a tithe of the height, and it gradually decreases to the caudal fin.  The oblong profile is highest at the third dorsal spine, whence it descends with a slightly convex curve to the mouth, which is low down—­the under jaw when extended, being nearly on a line with the belly.  The height of the tail between the vertical fins is equal to half the greatest height of the body.  The dorsal and ventral lines are both acute, especially the former, and the medial line of the nape continues acute to the orbits.