THE ENTEROPNEUSTA. 
649 









TABLE 3. 
Pt. flava, var. saxicola. var. maldivensis. 
No. of specimen (1) (2) (3) (4) (1) (2) 
Proboscis coelom..............-.-s0s» Spacious Not large | Fairly large as (3) Fairly well as (1) 
developed 
and with 
definite 
outline 
Wollarteoelomipmercc. sccsccecoecac asec Spacious Somewhat | Spacious Spacious Very as (1) 
occluded by spacious 
connective 
tissue 
Ventral proboscis septum ......... Nearly to as (1) as (1) as (1) Nearly to | Not nearly 
tip of tip of to tip of 
stomochord stomochord | stomochord 
Dorso-ventral proboscis muscles | Present Traces as (2) Absent Present as (1) 
Dorsal collar septum ...........0... Commences | Commences | Complete as (3) Complete Complete 
just anterior |°5 mm. behind) after 1st root after 2nd | after Ist root 
to 1st root Ist root root 
Ventral collar septum............... Complete in as (1) Present in as (1) Absent as (1) 
hinder part hinder part 
of collar of collar but 
not complete 
IRACeMOSC OLEAN <.c.-caccscessesssers Well marked | Well marked | Well marked | Distinct but || Small and as (1) 
butsmall and and and slightly |not lobulated || unlobulated 
unlobulated | lobulated lobulated 
Dorsal proboscis muscle decus- Distinet | Strong. Also|Well marked.) Strong but || Feeble. No as (1) 
sation a few ventral | A few ventral} no ventral || ventral cir- 
circular cireular cireular cular fibres 
fibres fibres fibres 
WMorsalinoots|s.cccn.ccs. casssecosseacoss *RRrr Rr RR RRR Rr R 
IRTODOSCIS| POLES) sere cascecescecease=: *Lr LR IR LR Lr IR 
WNervercord! (22 esscccssesceecaseses Lumen with | Lumen with Lumen Lumen with Lumen Lumen 
tendency to | marked ten-| continuous | slight ten- || continuous. | continuous 
obliteration | dency to dency to Slight ten- 
in middle | obliteration obliteration dency to 
part obliteration 
posteriorly 
Length of post-branchial groove ; a ee as Eyl 
Length of branchial region Fe a are 20 aS i 
Length of cornua x 100 = , : = be. ; 
Lenethofcollar 7077 yA 101 194 70 15°0 84 
= es of branchial ces. 33 5 5 38 1-01 1:20 
Circumference of cesoph. ces. 
SVU UICUIA ees vececnnseeccieessésconess Not more Not more Up to 9 Not more | = = 
than 5 than 6 than 3 
Length of branchial region is 2 
bts : 1-2 : 95 | 7 
Tengen of collar 95 5 1-16 92 134 1:70 








* See foot-note on p. 645. 


