34 SYRIAN MOLLUSCAN FOSSILS. 



sive bent raised lines, wliicli indicate in the progressive growtli of the shell 

 the presence of a shallow notch at the edge of the aperture, corresponding 

 on a small scale with the fissure of Pleurotomaria. These markings are very 

 like those which have given name to the palaeozoic genus Raphistoma Hall 

 (Palieontology of New York, I, p. 28, 1847). Coll. Bird. 



Localih/ and Position. — Abeih ; from an arenaceous portion of the Turo- 

 nian yellow marl. 



Colostracon curtum, sp nov. 



Plate III, figs. 4 a, b, c. d. 



Testa inverso-comca, longior qmun lutior, sjiira fere plana, ah anfradus ultimi 

 parte interiori vsque ad centrum viininic concants ; aufracius quaiuor vel qvinque 

 centrum versus amplitiidine ciiiiis decresceides ; vltimi luteribiis planis ante angidum 

 parum constrictis : apcrtura recta, amjustiuscula, antice latior : siiperjicies postice 

 striis minutis Jluctuosis, antice sidcis cxiguis cincta ; labnim simplex, tenuissimum ; 

 lahiimi amjustc ac tenuiter reflcxxim ; columella Icviter rimulata. 



Shell inversely conical, longer than wide, spire almost plane, very slightly 

 concave from the inner side of the last volution to the centre : whorls four 

 or five, rather rapidly diminishing in thickness towards the centre, hav- 

 ino- the sides flat and very slightly constricted just before the angle .• 

 aperture straight, rather narrow, wider in front : surface encircled behind 

 with minute wavy stri», before with light grooves ; outer lip simple, very 

 thin ; inner lip narrowly and thinly spread upon the columella, which is 

 slightly fissured. 



Single specimen. Length, 17 mm., originally about 20 mm.; width 

 12 mm. 



In the specimen from which the foregoing description is drawn, the 

 surface is spirally marked behind with minute wavy striao, and in front 

 by rather wide shallow grooves. Between the two extremities the shell is 

 corroded, but shows traces of lines intermediate in character between those 

 of the anterior and posterior parts, indicating that the whole extei'ior was 

 orio-inally covered with revolving lines which became anteriorly wider and 

 deeper. It seems probable that in its perfect state the front was produced 

 into an lo-like beak, as in the last species. Coll. Bird. 



Localii// and Position. — Abeih; from an arenaceous portion of the Turo- 

 uian yellow marl. 



