354 MAZATLAN UNIVALVES 



Maravignia, Aradas fy Maggiore, 1842. 

 Phasianema, Searlcs Wood, Crag Moll. 1842. 



Animal with two frontal lobes between the tentacles ; shell 

 umbilicated, sculptured, mouth semilunate. 



404. FossABtis TUBEBOSUS, n. s. 



F. t. "Fossaro angulato" simili, sed anfr. vi., quarum iv. 

 tuberosi, rubri, concentrice tenuissime lirati, interdum carinati ; 

 anfr. ii. normalibus, albido-fuscis, plus minusve tumentibus, 

 carinis et liris plus minusve irregulariter extantibus ; labio 

 excavato ; umbilico et staturd maxime variantibus ; epider- 

 mide interdum setosd. ^ 



=?Trichotropis, sp. 1. P. P. C., Cat. Prov. f 



Comp. Adeorbis scaber, Phil, in Zeit. f. Mai. 1848, p. 129. 

 (Hob. Panama.) 



The three individuals found vary extremely in form, markings 

 and umbilicus. They agree however in the remarkable char- 

 acter of the vertex, which is like that of (Tuberia) supralirata, 

 and is set rather slanting on the body whirls. These are 

 either regular, or suddenly bulging, as in the polymorphous 

 Dundry fossil, Cirrus nodosus, Soiu., and are marked with 

 irregular costse, two or more of which develop into keels. In 

 the spreading form the umbilicus is very large ; in the compact 

 state very small. A young spreading sp. measures '032 by "03, 

 div, 90j ; a larger compact one, long. "043, long. spir. '015, 

 lat. '38, div. 60. 



Hob. Mazatlan ; extremely rare, off Chama and Spondylus 5 

 L'pool Col. 



Tablet 1700 contains the two extreme specimens. 



405. FOSSABUS ANGULATUS, n. S. 



F. t. subovoided, tenui ; albido-fusca, atro-purpureo irregu- 

 lariter maculosa ; spird subacutd, anfr. iv. quorum duo nucleosi > 

 Iceves ; carinis angulatis circiter vi. quarum duce tresve extan- 

 tiores sunt, striulisque spiralibus creberrimis, ab epidermide 

 tenuissime cancellatis, eleganter exculptd ; umbilico magno, acute 

 carinato ; labro tenui, angulato ; peritremati continuo ; labio 

 mx excavato, haud plicato. 



