VERRUCA SPENGLERI. 521 



basi-carinal corner is more rectangular, and the whole valve 

 is nearly square : owing to the deep furrow receiving the 

 lower articular ridge of the scutum, the axial ridge of the 

 tergum is proportionally narrower but more prominent than 

 in V. Stromia; the uppermost ridge (formed by the occlu- 

 dent margin of the valve) projects, especially when viewed 

 on the under side (fig. 3 b), as a moderately sharp point. 



In the mouth, the lower teeth of the mandibles are more 

 distinct than in V. Stromia ; the lower part of the edge of 

 the maxilla is very prominent. In the second and third 

 pairs of cirri the terminal spines on the shorter rami are 

 coarsely pectinated ; on the sixth pair there are only three 

 pairs of main spines on each segment ; but these several 

 points, according to the analogy of other species, I should 

 expect to be variable. 



This species is alluded to by Bruguiere, in the 'Ency- 

 clopedic Methodique,' but was confounded by him with the 

 V. Stromia of Europe. 



3. Verruca Spengleri. PL 21, fig. 2. 



Moveable scutum, with a sharp, straight, medial adductor 

 ridge : fixed scutum ?iot larger than the fixed tergum. 



Hab. — Madeira, Mus. Lowe ; attached to shells. 



It would appear that the present species does not attain 

 quite so large a size as the more northern V. Stromia; the 

 walls are not longitudinally ribbed as is usual with this 

 latter species. The proportional sizes of the compartments 

 seem to be somewhat different ; the fixed scutum is either 

 equal to or even smaller than the fixed tergum, instead of 

 being larger, as in V. Stromia; but in young individuals 

 the proportions are reversed. In several specimens the fixed 

 scutum and tergum together were larger than the carina. 

 The rounded adductor plate of the fixed scutum is extremely 

 large. The lines of growth, especially on the moveable 

 opercular valves, are rather more plainly crenated than in 

 V. Stromia. In the moveable scutum the lower articular 

 ridge on the tergal margin varies a little in size, and is 



