188 HULLllTIN OF THK BURKAU OF FISHERIES. 



vi;RKicir).+;. 



Verruca halotheca, n. sp. 

 \V\. IV, lig. [>. 10. J 



Sh(>ll white, flatti'iicd above, with steep sides, ahiiost perpendieular to the base of attachment, 

 which has a rouncU'cl I'ontour. Surface moderately corrugated with cimcentric growth ridges. Mov- 

 al)le scutum small, flat, with an acute apex and three articular ridges, the middle one strongest. Mov- 

 able tergum larger, (piailrale, flat, with three strong imbricating articular ridges. Fixed scutum roughly 

 cjuadrate divided by an oblicpie sulcus into two nearly equal triangles. Fixed tergum of very irregular 

 shape, divided into ilu'ee triangular an'as; its umbo adjacent to that of the movable tergum, but not 

 (piite marginal. The carina articulates willi tlie rostrum Ijy means of three large and several smaller 

 teeth, forming a zig/.ag suture; each tootlvtermiiiales a ridge. It articulates with the fixed tergum by a 

 single tooth projecting into the tergum near the liase. The rostrum is irregularly cone-shaped, minus a 

 segment, in shape somewhat like the anterior valve of some chitons. It has several radiating ridges on 

 the carinal side, (ireatest rostro-cariiial length at base 14 mm., at umbones 12 mm., breadth 12.5 mm. 

 II<'ight from liase to apex of rostrum, fixed scutum or carina, 8 mm. 



Length of the straight rostro-carinal hinge of the opercular valves lU nun. Length of scutum from 

 litis line to umbo 5,5 mm. Length of tergum (i mm. 



Type, no, 32423 L'. S, National Museum, from station -lotid, norilieast ccjast of Hawaii Island, in 

 iUi'i fathotns, on a pebble of \nlcanic rock, 



A single specimen of litis large Verruca was olitained. It is clearly ilistinct from any of those 

 described liy Darwin, Hoek. or in Gruvel's recent monograph, though related to T'. trisulcata, spenghri. 

 etc. It is chiefly notable for the flat top, absence of salient ttmbones, and the generally inornate appear- 

 ance. It is the largest ]'rrnica yet descril)ed. A few detached valves of a small individual were taken 

 al station 3'jys. vicinity of Kauai l.-Liiid. in 22S to 235 fathoms, witli ('(tlDphragiitins and I'ircilnsiiia. 



CHTlWW.WAhAL 



Genus CATOPHRAGMUS So\\cil,y. 



This genus has hillierto l>ei'n known l>y two species; ('. ititbriratus Sowerby. from Atitigua and 

 ''. polyiiirriis Darwin fiiuii New Soutli Wales, botli (jf whii-h ar<' described in Darwin's monograph on 

 tile lialaniihe. 'Hie lir-i , ( ', iiiihricaliis. is a very rare liarnac le. liolli of the species are littoral, as,sociated 

 with or growing nu I'llrdclita and other shore forms. 



A third species of the genus, from still anotlier part of llie world, is re|ire,sented by cerlain iiiulilaled 

 individuals dredged by lln- Albatross near Kaitai in about 230 fathoms. It is very distinct from the 

 otliers by its well develoi>ed caudal appeti(Uige — that organ lieing absi'nl in ('. polyntcrus, very small in 

 ('. iiiihricdtiix. Moreover, llie valves show many points of ilifleriMice, and the mandibles, inaxilUe, and 

 cirri are uiiliki' iii various details. 



Catophragmus darwini n. sp. 



[PL v,| 



(ieneral loriii '<\ llie animal uncertain, since it is known only by broken capilula, which are Jialaiius- 

 like, made up of valves of dense and porcelain-like texture; white. There are at least three whorls 

 of plates, the first whorl cotisisting of scuta and terga, the second of carina, lat era. and rostrum, the third 

 of imbricating ba,sal plates. 



The scutum (pi. V. fig. 7 otttside, fig. 4 insidei, is Iriangular, sculiilured with rather widely spaced 

 riblets parallel to the ba.sal margin. The oicluileiil and ba.=al margins are straight. The tergal margin is 

 somewhat convex, and on the apical half bears a projecting wing or articular ridge with serrate edge 

 and closely grooved an<l costate surface. Tins wing projects iTiio the ;ulicu!ar groove of the tergum. 

 Inside the scutum .-Imws a beveled, oblifpti'ly costate and thick ocrliid.ni border, a slightly refle.xed 

 apical area, and a series of line sharp grooves I'unning inward from ilie leci Iku the free edge of the articular 

 ridge or wing. The scar of ilie ad duel or muscle is not not ici ■able, 'llie len^ili nf the senium is 5.3 mm. 



