148 



in other characters, as for example in the shape of the rostrum, but the differences are more 

 obvious. The carina and the fixed valves do not at all resemble those of V. nexa. 



Verrnca conchula, var. minor, nov. var. PI. XI, hg. 16 and 17. 



In the Kei Islands Archipelago two small specimens of a Verruca were dredged. These 

 show great resemblance to the V. concJiula just described but differ, however, in certain 

 characters from the specimen used for that description. I consider this form to be a variety, 

 since I do not believe that the differences are caused by difference in age, as might be supposed, 

 because the animals from the Kei Islands are considerably smaller, their largest diameter 

 measuring 3 mm. only. Although the general shape corresponds fairly well, the carina has a 

 somewhat different form, in consequence of the apex not only projecting beyond the basi- 

 carinal angle of the tergum, but being also distinctly recurved. The rostrum is different also, 

 since the ridges, which in V. conclmla are disposed to a large extent on the circumference of a 

 central part which I compared with the palm of a hand, in this variety can be foliowed, though 

 not very distinctly, over the whole surface of the valve. Finally there is an important difference 

 in the way in which the fixed scutum and tergum in the variety are interlocked, each valve 

 having distinct articular ridges which interlock between the articular ridges of the other valve 

 (fig. 1 7). Such indentations are not seen along the adjoining margins of the fixed scutum and 

 tergum in V. conclmla. 



It is possible, that the variety described here may later be found to represent a different 

 species, and I consider this to be more probable than its being regarded as a younger specimen 

 of V. conclmla. 



- This small species was collected at : 



Stat. 254. December 10, 1899. Lat. 5°4o'S., Long. I32°26'E. Depth 310 m. Bottom : fine 

 grey mud. Two small specimens attached to a rounded stick of unknown nature. 

 One specimen only is complete, the other has no moveable valves. 



6. Verruca casiila n. sp. PI. XIII, fig. 14 and 15. 



Shell white, walls perpendicular to the surface of attachment, moveable valves almost 

 parallel to the walls. Moveable scutum with two articular ridges running close together, moveable 

 tergum with two articular ridges also, but separated from one another by an interspace of 

 triangular shape. Apex of the carina pointed, but hardly projecting freely: that of the carina 

 neither pointed, nor projecting. Rostrum and carina articulating together by means of a well- 

 developed and broad tooth on the rostrum, fitting between two feebly-indicated teeth of the 

 carina. Basis narrow, oval. 



This species is represented by a single specimen of small dimensions. lts perpen- 

 dicular compartments are well-developed ; in consequence the shell when seen from the side 

 of the moveable valves has the shape of a quadrangular case with a triangular, pointed 



