17 



March 11, 1845. 



Rev. John Barlovv, M.A., F.R.S., Sec. R.I., iu the Chair. 



Four specimens of Fish from the hot springs of Thermopylae were 

 presented to the Society by James Wyllie, E?ą. Mr. Yarrell stated 

 them to be Cyprinoid Fishes of the genus Leuciscus, but from thelr 

 highly desiccated statė and very small size it was impossible to refer 

 them to a definite species. 



A paper by Sylvanus Hanley, Esq., lyas read, containing descrip- 

 tions of two nevv species of Donax : — 



DoNAX ASSiMiLis. Don. testd cuneiformi, magis minusve crassd, 

 antice compressd, postice ventricosd, valde incegmlaterali, lividd, 

 albo-violūscente, aurantid aut flavidd, zonis saturatioribus aut vio- 

 laceis plerumąue pictd, radiatim striatd ; striis haud confertis, 

 antice simplicibus, postice elevatis et decussatis ; margine ventrali 

 crenulato, haud arcuato, antice sursum acclinato ; dorsali, antici 

 subdeclivi subrecto aut convexiusculo, postice suhrecto et valdi" de- 

 clivi ; latere antico producto, ad extremitatem rotundato et atte- 

 nuato ; postico perbrevi et inferni angulato ; costd umbonali sub- 

 angulatd ; pube decussatd, et costelld ad extremitatem dentiferd, 

 scEpe radiatd; ligamento prominente-et satis magno ; superficie in- 

 ternd in adultis, prope marginėm violaced ; dente laterali antico 

 haud remoto, postico subapproximato. Long. 1 ; lat. 1*55 poli. 

 Hab. Panama. Mus. Cuming, Hanley, &c. 



Very variable in colouring, often with a short purple perpendicular 

 ray upon the umbones ; sometimes witli three or four pale rays on a 

 darker ground, but usually uniform and only marked when aged, with 

 the rib-lLke stria projecting at the margin likę a tooth. ITiis latter 

 character and the identity of its sculpture render the species liable 

 to be confused with dentifera, but the greater tenuity and less elon- 

 gated shape of that shell is preserved even in the younger specimens. 



DoNAX LUBRicus. Don. testd cuneiformi, compressd, solidiusculd, 

 valde inceguilaterali, nitidissimd, lividd aut albo-violascente, antice 

 l<Evigatd, postice striis radiantibus ornatd ; margine ventrali ex- 

 iliter crenulato, conveso aut convexiusculo ; dorsali, utringue sub- 

 recto, antice declivi, postice valde declivi ; latere antico attenuato, 

 ad extremitatem rotundato; postico perbrevi et infernP. obtuse 

 angulato ; vulvd rugis confertis concentricis, striisąue exilibus ra- 

 diantibus, eleganter decussatd; costd umbonali subobtusd; natibus 

 acutis ; dentibus lateralibus obsoletis. Long. 0*6 ; lat. 0*8 poli. 



Hab. ? Mus. Cuming. 



Peculiar for uniting a smooth surface to a crenulated margiu. 

 No. CXLV. — Procbedings of the Zoological Socikty. 



