178 Dr. Richardson's Contributions to 



Atherina hepsetoides (Nob.), Tasmanian Sauclet. 



Several examples of an Atherine, corresponding very closely 

 in external form with the Mediterranean Sauclet, were sent 

 to me from Port Arthur by Mr. Lempriere. Long maceration 

 in spirits and friction against larger fish during the voyage 

 home have destroyed the colours of the specimens, but their 

 forms are tolerably perfect, and a sedulous comparison of the 

 specimens with the figure and detailed description of the 

 Sauclet in the ' Histoire des Poissons ? elicited the very few 

 tangible differences which are comprised in the following 

 notice. 



The body is rather more elevated than that of the Sauclet, its 

 height forming only the eighth part of the total length ; the nape is 

 also a little narrower, but the roundish form of the body, the pro- 

 portional length of the head, 'the comparative size of the eye, and 

 its position removed its own breadth from the tip of the snout, the 

 great protractility of the intermaxillaries, the minuteness of the teeth, 

 the total recession of the maxillary beneath the edge of the triangu- 

 lar preorbitar when the jaws are closed, and the numbers and form 

 of the dorsal rays, are all exactly as in the Sauclet ; the first dorsal 

 has likewise the same relative position above the middle of the ven- 

 trals as in that species, but it commences at a point nearer to the 

 tip of the snout than to the base of the caudal, instead of exactly in 

 the middle of the fish. Moreover, the anal fin contains two rays 

 above the number ascribed to hepsetus in the 'Histoire des Poissons.' 

 There are four oval cells on each side of the flat forehead and snout, 

 with a lengthened triangular space between the rows, bisected by a 

 slightly elevated, acute, mesial ridge. 



The rays of the fins are dotted with black ; the silvery lateral band, 

 which retains its colour and form after the scales are removed, is 

 similar in breadth and situation to that of hepsetus, and the back is 

 ornamented with black specks ranged round the edges of the scales. 



Rays:— D. 9|-1|11; A. 1|14; C. 15f ; P. 15; V. 1|5. 



The interior of the peritoneum and the ovarium are black. In 

 the specimen examined the ova w r ere numerous and large, occupying 

 more than two-thirds of the cavity of the abdomen. The spine con- 

 sists of 48 vertebras, whose bodies have an exact hour-glass form. 

 Several of the anterior spinous processes have dilated semi-membra- 

 nous edges, which are gradually restricted as they recede from the 

 cranium. At the 20th vertebra the lateral processes are bent down- 

 wards, and unite to form a canal for the passage of the vessels, and 

 perhaps for the reception of the point of the air-bladder. At the 

 twenty-fourth vertebra the change from lateral to inferior spinous 

 processes is complete. There is a slight membranous expansion of 

 the intermediate processes, but it is not very evident. In A. pres- 

 byter the transverse processes, from the 25th to the 30th vertebra, 

 expand and unite below, to form a funnel, which encloses the end of 

 the air-bladder. In hepsetus a less conspicuous dilatation of the 

 processes of four vertebras commences at the thirty-third. 



