2">() lAMlOKNlA AfAKlMY Dl' Si lliNCKS. 



elliptical; outer lip lliickt-nftl, smooth within; iiiiuT lip incrustcd, smootli; cohimclla only faintly 

 sqimniose, curvi-tl and slightly twisted; canal ratluT short, narrow. 



Pi^iffisions. — \.(tn^. 33 mm. ; lat. 15 mm.; body-whorl 23 mm.; aperture, including canal, 

 i,S mm.; canal 7 mm.; detl. 44 degrees. 



'I'ln' liiijii'st of the Trophonn so far fotmd in tlii.s locality. I'lic adult of litis 

 slii'll resfml)U'.s var. /tnicnrnor, hut is (listiiij;iiishai)l(' ffom that species hy its larger 

 size, heavier sliell, more proiniiieiit spiral ridges, |)r()porti()iially shorter canal, and in 

 haviiii; tlie angle near tin- niiddic of ilic wliml, !:itlicr than posterior to lln' middle; 

 distingnishahle from T. Ktnditi hy heavier shell, more inimerons and much heavier, 

 lower and mi>re rounded, tratisverse ridges, shorter canal, and hy having the angle in 

 the middle of the whorl. The young of 7'. ceirik'nsis resemhle.s 7'. pcdrnnna .some- 

 what, hill tiiay he distingiii.siied from that species hy its heavier shell, ntore depressed 

 outline and much shorter canal. Ait adult found at Los Cerritos lias fewer transverse 

 ridges and a higher angle than the type. Type from lower San Pedro series of 

 Deadman Island. Said i)y Dr. Dall to he tiear T. rratic/i/'i/>i>i Fahricins. 



One adult specimen (type) and live jtitiiors fotind in lower San Pedro serie.s 

 at Deadittait Islatid; one specimeit fiditt Los Cerritos in ui^per San Pedro series. 

 The specimen figured is the type, which is from the lower San Pedro series at 

 Deadman Island, and is now in tlie Uttitcd Slates Natiotial Musetiiti. 



Pleistocene. — San I'ldio (.\titold). 



250. Trophon (Boreotrophon) gracilis Perry. 



I'l.A-ri; VI, Fig. 8. 



Polyplex gracilis Pickkv, Coiuii , I'i. IX, lig. 4. 



Tropkon iiiit/lifoslatus (mA i>i\\'nUH.) GwiK. Va\. C;i\.,\o\. II. p. 70, 1869 (in part). Cooper, 7th 

 Ann. Kept. Cal. St. Miii., 1S88, p. 268 (in pan;. 



Shell of medium size, (u-.iforni; sp're elevated; whorls five or si.x, sharply angular, crossed 

 by eight or nine frill-like varices, which fle.x forward and are only slightly coronate on angle; surface 

 smooth; suture deeply impressed, giving tabulate appearance to upper p.irt of whorl; a[)erturi 

 elliptical; outer lip efTuse, smooth within; inner lip smooth; columella long, slightly twisted; canal 

 long, narrow, recurved. 



Dimensions. — Long. 26 mm.; hit. 13 mm.; Ijody-wlioil 19 5 mm ; aperture 16.2 mm.; canal 

 7.7 mm.; defl. 62 degrees. 



Distingui.shahlc hy frill-like varices and lack of spiral sculpture. Specimens 

 identified h}' Dr. Dall. This species is the 7'. mvlticostatufi of most western col- 

 lectors. It differs from that species in having fewer, but more prominent varices, 

 and in being a broader shell. 



Rare in Pliocene and lower San Pedro series of Deadman Island. Foiitid 

 also in the Pleistocene at bath-house, Santa Barbara. The specimen figured is from 

 the I'lioeene of Deadman Island, and is now iti the collection of Delos Arnold. 



JAring. — Circumpolar; Sitka to Monterey (Cooper). 



Pleistocene. — Santa Barbara (Cooper; Arnold): San Pedro (Arnold). 



Pliocene. — San Pedro (Arnold). 



