1916] Moody: Fauna of the Fernando of Los Angeles 



51 



Description op Species 



EPITONIUM (OPALIA) RETIPOROSA Carpenter 



Plate 1, Figure 3 

 Opalia retiporosa Opr., Brit. Assn. Eept., p. 146, 1863 



Shell small, elongate, thick ; spire greatly elevated. Including the 

 nucleus there are ten rounded whorls ornamented with fourteen 

 irregular, rounded varices. Numerous fine, equally developed spiral 

 and transverse ribs intersect at right angles forming a pronounced 

 though minutely reticulated structure over the entire surface ; deep 

 holes occur between the two systems of sculpture ; the transverse ribs 

 pass obliquely over the varices. Suture depressed, distinct. Aperture 

 oval ; the nacreous layer is slightly reflexed over the large mouth-varix. 



Dimensions : longitude, 9.2 mm. ; latitude, 3.4 mm. 



So far as known this is the first time that this species has been 

 reported as a fossil. The original description of the shell is very 

 brief, and, as the single individual found in this deposit is a perfect 

 specimen, it has been thought well to redescribe and figure it. 



SIPHONALIA GILBERTI, n.sp. 

 Plate 1, Figures 5a, 5b 

 Univ. Calif. Coll. Invert. Palaeont., no. 11077. Type locality, Fourth and 

 Broadway, Los Angeles. 



Shell fusiform with highly elevated spire. The four or five spiral 

 whorls are ventricose, and distinctly angulated above the middle, with 

 the angle bearing nine or ten rounded nodes which are faint on the 

 body-whorl but strongly and sharply marked on the succeeding whorls ; 

 these nodes die out rapidly above and below the angle ; below the 

 angulation on the spiral whorls the walls are vertical ; region between 

 the angle and the upper suture excavated, producing a collar-like 

 effect. Three systems of spiral sculpture ornament each of the whorls ; 

 one unit of sculpture consists of two subquadrate ribs about 1.2 mm. 

 wide and separated by an interspace 3.9 mm. wide ; medially between 

 these ribs is a much less prominent rib about 0.8 mm. wide, and 

 flanking it are two yet smaller ones separated from it by deep, 

 rectangular grooves and from the main rib by less pronounced grooves. 

 On the body-whorl there are seven units of the major sculpture below 

 and one on the angle, while six ribs of equal strength mark the 

 excavated region between the angle and the suture. Primary and 



