32 CEUETOPLEURA. 



plates triangulate ; sinus deep ; margins of the valves simple, the 

 median having 1, the terminal valves about 7 slits. (Qyr.) 



Length 4J, breadth 3, alt. t mill; divergence 110. 



Muzatlan, on Spondylus calcifer. 



Lepidopleurus bulletins CPU., Mazat. Catal. p. 195. Chcetopleura 

 bullata CPR. MS. L. bulletins var. calciferus CPR., 1. c. p. 196. 



One fresh specimen (somewhat crushed in extraction) and a few 

 perfect valves were found of this species, which is characterized by 

 the very strong row of tubercles, (like pebbles) which lie on the 

 diagonal line ; by the rows of somewhat strong tubercles on the 

 central area, running perpendicularly from the diagonal towards the 

 jugum and the granules over the whole surface, somewhat corru- 

 gated on the jugum. The internal plates of all the valves have an 

 external projection from the outer surface, as in L. sanguineus. 



Carpenter describes a larger specimen in ms. as follows : Mucro 

 median, scarcely elevated. Vermilion and olive, very irregularly, 

 vividly maculated. Interior: posterior valve with 9, central valves 

 1, anterior valve 11 slits. Teeth acute. Eaves projecting, pectin- 

 ated by the sculpture. Sinus moderate, high, laminate. Girdle 

 smooth, ornamented with sparse hairlets. Gills subambient, scarcely 

 reaching the head. Abedhas Keefs. (Mus. Yale College). This 

 specimen is about 15 mill, long, GT broad, divergence 125. It 

 agrees in most respects with the very young shell described in Maz. 

 Catal., but is much longer in proportion. 



Var. CALCIFERA Cpr. 



Lateral areas tuberculate, without pustules ; diagonal line peb- 

 bled ; central areas with lines of tubercles irregular, tubercles smal- 

 ler. Hairs of the girdle larger, very close. 



Mazatlan* 

 C. BEANII Carpenter. 



Shell ovate, elevated, brown-olive or maculated with whitish and 

 bluish. Intermediate valves strongly mucronate, interstices curved, 

 margins somewhat rounded. Posterior valve depressed, excavated, 

 the mucro small, superior; jugal and lateral areas indistinct; sur- 

 face covered with granules and ornamented with small close points. 

 Sutural plates large, curved; sinus flat; insertion plates acute, the 

 intermediate valves with lj terminal valves 10 slits. Girdle hairy, 

 spines small, erect, flat. 



Length 5:|, breadth 3i, alt. 1 mill.; divergence 110. 



Mazatlan* 



