2. AMPnisiLE. o'27 



the pectoral fin which equals that between the operculum and the 

 pectoral ; a rudimentary pubic bone is ^^8iblc within the friu<^o*. 



The vent is situated verj- far backwards, immediately before the 

 anal fin ; its distance from the base of the caudal is less than that 

 between opercle and pectoral. 



The coloiu" of preserved spcimens is uniform whitish. 



Anatomy. — The first organ which makes its appearance after the 

 removal of the lateral portion of the cuirass is the air-bladder : its 

 position and its extent are easilj- ascertained by holding the fish 

 against the light, when an oblong oval spot will be visible which is 

 more transparent than the rest ; it commences on the same level 

 %vith the root of the pectoral and extends backwards to the fourth 

 rib. Tlie oesophagus passes gradually into the stomach, which is 

 situated below the air-bladder ; it does not appear to be much wider 

 than the intestine following ; the latter makes a single complete 

 circumvolution and then proceeds to the vent. Ovaria and testicles 

 are situated behind the air-bladder. 



The structure of the vertebral column is extremely singular, and 

 perhaps unique among the Acanthopterygians. The abdominal 

 portion is more than four times as long as the caudal ; nevertheless 

 it is composed of only six vertebrae, whilst the latter consists of 

 fourteen. These abdominal vertebree are extremely slender, the 

 third alone being nearly as long as the whole caudal portion •; they 

 have a slight ridge superiorly and inferiorly and on each side ; the 

 whole portion lies in the uppeimost concavity of the dorsal cuirass. 

 The caudal vertebite are extremel}' shoi-t, and the strength of their 

 neural and haemal spines is in proportion to their size. 



I am of opinion that the dorsal cuirass is not a dermal production, 

 but formed by modified parts of the endoskcleton ; its composition, 

 the number and position of its single parts, and, finally, the first 

 dorsal spine, which in A. punctulata is so singularly attached to it, 

 favour this opinion. The plates which occupy the vertebral line 

 would correspond to the nem-al spines, and the lateral plates on 

 which the ribs are susjiended, to tlie parapophyses. Amplnsile may 

 be considered as a Chelonian fonn among fishes. 



2. AmpMsile punctulata. 



Amphisile, sp., Klein, Miss. Pise. iv. p. 28. tab. 6. fig. 6. 

 ? Centriscus scutatus, ForsJc. DescrijA. Anim. p. xvii. 

 Amphisile punctulata, Bianconi, Spec. Zool. Mos. fasc. x. 1854, p. 221. 

 tab. 1. fig. 2. 



brevispinis, Peters in Wiegm. Arch. 1855, p. 259. 



punctata, Kner in Sitzgsber. Wicn. Acad. 1860, xxxix. p. 534. fig. 2. 



B. 4. D. 3 I 10. A. 13. C. 11. P. 12. V. 4. 



The first dorsal spine is joined to, and not quite half as long as, 

 its internenral ;' the distance of the posterior margin of the oper- 

 culum from the root of the pectoral equals its distance from the 



» According to Kner, tlie ventral fins are united and tlie middle rays are pro- 

 longed in the male sex. 



