On new Species of Ilistcrifla?. 05 



Wealflon fossil just described to prevent its reference to an 

 Elopine or Clupeoid fish ; but as tlie European AVealden 

 fisli-fanna is essentially of a Jurassic type*, the specimen is 

 more likely to belong to a member of the L"ptolepida3, with 

 which it equally agrees. The skeleton of the trunk resembles 

 that both of Leptole/iis itself and of yEthalion ; but the lack 

 of jaws prevents an exact determination of the genus. The 

 number of the vertebras exceeds that of all known species of 

 both genera except ^thalion Vidalif, and the relative short- 

 ness of the hinder caudal, as well as the anterior abdominal 

 vertebral centra, is a feature peculiar to the new Wealden 

 iish. The tins, as described, also distinguish this fossil from 

 all species with which it can be compared. It therefore 

 represents a new species, which I projjose to name Leptolepis 

 valdens'is until the discovery of the head determines its 

 precise generic position. 



EXPLANATION OF PLATE I. 



Fiij. 1 . Leptolepis vahktisis, sp. n. ; right side view of type specimen, one 

 lialf nat. fize. — Weald Clay; Southwater, Sussex. [P>rit. Miis. 

 Mi>. P. 10440.] a., anal fin ; br., branchios*ef,^il rays; c, caudal 

 tin; c/., clavicle ; rf., dor.sal fin ; /*//«., hyoniandibular ; «/>., oper- 

 culum ; ;;/('., pelvic tins ; }>"/)., preopercukuu ; pt., post-temporal ; 

 sc/., siipraclavide ; soj)., suboperculuin. 



Fi'i/. 2. Ditto ; caudal vertebras of same specimen, nat. size. 



XVIII. — On nexc Species f)/" Ilistorida; and Xolices of others. 

 By G. Lewis, F.L.S. 



This is the thirty-first paper of this series, which dat^s from 

 the year 1884. In the Histeridaj the absence or otherwise of 

 prosternal stria3 is sometimes of great significance, anil serves 

 to distinguish both genera and species. Thus, in Teretrio- 

 soma the strife are wanting, in Ttretrius they are well marked 

 and very useful as specific characters; and in Paromalus, as 

 the genus is now defined, the prosternal keel is marginate — 

 that is, the striie meet at both ends. In Grammostetlius^ 

 also, the ])rosternal strite are of importance, as being con- 

 stantly similar in a series of fourteen cognate species, but 

 which possess, however, inter alitij good specific characters. 



* A. S. Woodward, " Note on the Afliuitios of the English Wealden 

 Fish Fauna," Oeol. Mao-. [4] vol. iii. (1890) pp. U9-71. 



t II. E. Sauva^'e. " Notlcia sobre los Peco-. de la C'ah'za lito-rrafica do 

 la Provincia de Lc'-iida," .Mem. II. Acad. Cienc. Larceluna. [uj vol. iv. 

 no. 35 (,l'J03;, p. IS, pi. ii. liji. 2. 



