Dr. W. T. Caiman on 



cavity and lies on the upper surface of the adductor, in 

 S. sguamuliferum the males which I have examined were 

 attached in the fossa between the margins of the two scuta, 

 external to or below the adductor muscle*. 



Scalpellum {Scalpellum) ecaudatum, sp. n. (Text-fig. 2.) 



Locality. Lat. 7° 35' S., long. 114° 30' 30" E. (Java Sea), 

 73-175 fath. C./S. c Recorder.' 1 ? (holotype). 



Description. — Capitulum compressed, rather elongated. 

 Valves 14, all in contact, covered with a thin cuticle which 

 does not conceal the sculpturing and carries minute setse 

 scattered, for the most part, in rows along the lines of 

 growth. All the valves boldly sculptured with ribs radiating 

 from the umbones; the lines of growth marked by fine and 

 inconspicuous stria;. Tergum rather more than twice as long 

 as wide, occludent margin straight, scutal margin nearly so, 

 carinal margin convex, becoming straight or faintly concave 

 near the acute apex. Scutum twice as long as wide, occlu- 

 dent margin convex, other margins straight, apex slightly 

 overlapping tergum. Carina less than five times as long as 

 it is wide at the base, evenly curved, with the umbo apical, 

 entering between the terga, with a flat roof bordered by 

 strong ridges ; parietes rather deep, sloping inwards. 

 Upper latus quadrangular, scutal margin very slightly con- 

 cave, longer than the others, which are straight. Rostrum 

 small, triangular, overlapped at sides by rostral latera. 

 Rostral latus more than three times as wide as it is high, 

 with a pair of horizontal ribs converging to the umbo. 

 Inframedian latus very narrow, the sides converging to the 

 umbo, then diverging slightly in a small apical extension 

 beyond. Carinal latus with the recurved umbo projecting 

 behind and to the side of the carina; the convex margin 

 below the umbo less than half as long as the straight margin 

 above it Avhich abuts against the carina; the two latera meet 

 below the square base of the carina (fig. 2, B). 



Peduncle a little shorter than capitulum, closely set with 

 imbricated scales in about 14 longitudinal rows of 11 scales 

 each. 



* The statements as to the place of attachment of the males in 

 the genus Scalpellum in my account of the Crustacea in Lankester's 

 'Treatise on Zoology' (pt. vii. fasc. 3, p. 119) are, unfortunately, mis- 

 leading. The less-modihed males are, as a rule, attached in the position 

 descrihed above for >S. squamuliferum. The more highly modified males 

 are usually lodged in fossettes on the scutal margins. I know of no case 

 where they are placed far within the mantle-cavity in this genus. 



