262 AMERICAN JOURNAL 



inner corner of one tentacle to the other. Behind that line both 

 head and tentacles are whitish. 



The tentacles are short, stout, acutely pointed, and somewhat 

 granulosa. The eyes are very small on the outer edges of the 

 tentacles, which have a prominent tubercle on the inner edge of 

 each. 



The muzzle is short, stout, and transversely oval. Its outer 

 edge is somewhat striate and produced into a frill. Inside of 

 this, around the circular mouth, the disk is granulose and deeply 

 radiately furrowed. Just inside the mouth, the edge of the jaw 

 is perceptible, and arches over the lateral lips of the buccal 

 mass. 



The viscera are small in proportion to the size of the animal. 

 The ova were of a greenish color. The renal organ extended 

 over a fourth of the area of the back between the muscles. 



The range of this species is from the vicinity of San Francisco 

 to Central America. It is especially abundant and fine at Mon- 

 terey. Some of the specimens which I obtained there were 

 nearly three inches long. Put into a pitcher half full of sea 

 water, with a number of other mollusks, the majority of this 

 species crawled out during the night and were found on the out- 

 side of the pitcher, and even on the wooden floor, in the 

 morning. 



Genus SCURRIA, Gray. 



Scurria, Gray, P. Z. S. 1847, p. 158. Guide, Moll. p. 171. 

 Chenu, Man. de Conchyl. i, p. 375. 



< Scurria, Moerch, Cat. Yoldi, p. 145, 1852. Cpr., Lect. p. 



71. H. and A. Ad., Gen. Rec. Moll, i, p. 460. 



< Aemcea^ Woodw., Man. p. 155. 



Scurra, Gld., Expl. Exp. Moll. p. 357, 7wn Esch. 

 Acmcea, sp. D'Orb., Voy. Am. Merid, v, p. 478, 1846. 

 Helcioii^ sp. ib., p. 703 ! 

 Lottia, sp. ib., pi. 64, vol. ix ! ! 

 Not Scurria^ Cpr., Am. Journ. Conch, ii, p. 345 = Acm(£a sp. 

 Animal with an accessory branchial cordon extending entirely 

 around the body between the mantle and the foot. Teeth re- 

 sembling Collisella A. Formula yj^^^-J^v 



In this genus the cordon is complete as in Patella, while the 

 dentition and branchial plume show its true place to be in the 

 Acmceidce. There does not appear to be any grounds for the 

 distinction drawn by Dr. Gray between the cordon in this genus 

 and that of other Patellae. In Scurria mesoleuca they are ab- 

 solutely identical in form and arrangement with those of Lottia, 

 excepting that they are not interrupted in front as in that genus. 



