HXI'LANATION Ol' I'LA'PES. 



ri,ATK XXIII. 

 Tirela oraxHaifUoKifx CoiinMl. 

 'ry|'i<':il loriii, iiiiliii'al hI/.o. Stic i);ino;{7l. 



I'l.ATK WIV. 



(All li^iirtiH niitiinil lsi/.(^.) 



I'Mfj. 1. rirela craimatello'KlcK Conrad. Oiilliiie of .tii uiiiiHiially short triangular 



oxuni])1o. Soo page S77. 

 2. Outline* oC a s]>(MiniiMi from San Did^o — niuili ])rodn('0(l anteriorly. So^^ 



l>a>>o :{77. 

 !i. Outliiir of II lypical nxaniiiiii from Santa Monica, tlalifornia. Soo ])aji;o 'Ml. 

 I. Outline of . in unusually tlont^fttod specimen. Soo pajj^c* :{77. 



I'l.ATIO \XV. 



Fiff. 1. Tinlii criinKdlflliiitlfs (Ut\\rtu\. 



A s]ic('inmn from San l)icf;<i with the rij;ht valve aiul part of the rij^ht 

 ll,i)i of the mantle removed to show the soft parts. The arrows show 

 tlm dire(^tiou of the siphonal current. The heart, jtorforated by the 

 intestine, is seen abovt* the frills. The anal tMul of the intestine* is free 

 in the atrium of the anal siphon. The distal margin of the hrauchial 

 si])h()n is merely granular, of the anal siphon ])]ain. The former is opaeine 

 white, the latter translucent white, hotli marked with black dots around 

 theorilicos. 'I'lie foot is livid, tin* (idgc llesh color, Imllatt*, and wrinklctl, 

 the sides \ertically wrinkled anil granulate. The gills llesh (M)lor, th<i 

 h»*art orange, pulsating once every ten seconds. The adductor muscles 

 are reddisii, tin* nuinlle dark flesh color, with tli»< edge i)alc waxen white 

 and wrinkt(Ml. The body mass is livid llesh color, the palpi small, single, 

 twist<*d, distally more or less bifid. The intestine is white* externally. 

 Drawn from life by Mr. William II. Dall; two-thirds natural size. 

 1((. Sli(*tch of a. curious tr.inslueent body, aicting as a emit or gizzard, internally 

 situated behind the oral orifice. The uppiu- or transverse ])ortion over- 

 hangs f he lower like a li]» and aliment enters the organ below it. This lip 

 is eonfinuous with the tubular jiart behind. The figure is of natural 

 size. Drawn from life l)y Mr. William H. Dall. Tin* spt*cinien from 

 which these fignn>s Avere taken was collected at San Diego, (^aliforniii, 

 'MX 



