from Southern X'njfr'o. Vy^ 



The shnjte of the anterior etui, its cumpresaoil cliar ictcr, 

 ami the nioie or less vertical umljo would siig:4"e.st a relatioii- 

 sliip to probably a young tVirm of Lutraria eUlptica, 

 L-unarck, a spccifs occurring in th^ Pliocene bo. Is of Europe 

 aiiil Kiii;lanil, and which, njoreovor, exists in the Mi-di- 

 Itrrancaii. 



Ctisi'i'ihuia ct". rosffd/a, Speiij^lei-, s[». 

 (PI. VI. H4. 12.) 



Mi/o ro>tr<it<i, Spengler, Skiivt. natiu-hist. Selskab. Kjubi'iiliavii, 17i»3, 



vol. iii. i>l. ii. tig. 16, p. 42. 

 C'iiy)iil(iri(t roftratu, Sai;io, Moll. Teiz. I'iemonte &c., UJUl, vul. .wi.v. 



pi. xxvi. tigs. 35-37, p. li*4. 



Iiemarkn. — There is oi;ly a single specimen to represent 

 this form of Pelecypod, which consists of a right valve of 

 subtrigonal contour, with a marked anterior globosity and a 

 narrowly rostriform extension postero-ventrally, thesculplure 

 consisting; of delicate and irreo-ular striations on a concentric 

 basis, without any evidence of radial ornamentation. The 

 basal border is strongly arcuated in front, becoming after- 

 wards widely sinuated as part of the produced posterior 

 ( xtension. 



I )imeiisions. — IIei<:ht = 9, lenL!'tli = 15 mm. 



\Vith only one example it is ditlicult to say whether it 

 ."hould be placed with {)\\\Vs cus^piduta ov 'S\)t\\^^\<dv''s rostrata. 

 both species being regarded by some authors as synonymous 

 and having a similar range in time, viz. from the Upper 

 Tertiaries of Europe to the recent period. 



Darnea lagosiensis, sp. n. (PI. VI. tig. 13.) 



J >e^criptiov. — Slull subcylindrical, thin, inequilateral, 

 umbo at one-third distance of entire length ; anterior end 

 rounded, closed, narrow; posterior region extended, acumi- 

 nate; postero-umbonal margin elongatcly concave; antero- 

 dorsal margin reflected ; ornamented with equidistant radial 

 costaj (about 2-3) of considerable obliquity, occu[)ying about 

 three-quarters of the surface and crossed by nearly equi- 

 distarit growth-lines which at the junctions show obscure 

 thickenings or tubercles; posterior surface furnislied with 

 lines of growth only. 



Diniensions (largest specimen). — Height = 15, length = 

 i6 mm. 



Remarks-. — This fovm is apparetitly closely re'ated to the 

 rtcent Pliolas Candidas of Liinueus, the type of Risso's genus 



