NEMERTINEA— BAYTJS. 



110 



is somewhat 1,-irL^ci- tlwni llic type specimens, the Imdy ineasuriiiii,' 8 mm. in length, and 

 .3 mm. ti-i>m si(h' tn side at the widest part, which is aliout the middle. Tlie animal 

 tapers towards the head and tail. The dorsal surface is couve.x, the ventral surface 

 concave. The prolioscis was e.xtruded to a distance of .'5 mm., l)ut is now broken off, 

 and a microscopic preparation has been made of it 

 to show the armatin-e. 



Sevei'al of the specimens are very minute, 

 measurini;' onl\' about i2 mm. in length. 



The coloration (in spirit) is as follows : the 

 dorsal side is of a \-ellowisli flesh-colour, with a 

 distinct reddish-brown pigmented median stripe ; 

 the ventral side is of a pale ochreous yellow. 



The four large eyes have been made out 

 by clearing in creosote. The two on either side 

 lie close together, one beliind the other. (Te.xt- 

 fig. 1.) 



Internal Anatomy. 



/ mm 



Pic. 1. — PioxtiiiHa unilineaium : dorsal view 

 of the anterior end, magnified, showing 

 the eye.s (E.) 



The anatomy has not Ijeeu fully worked out, 

 as serial sections have not lieeu cut. A few transverse sections taken l)y hand reveal the 

 following characters : 



Bo<l'/->rii//. - The extei'ual epithelium (PI. I, fig. 8, Ep,) consists of very tall cells, 

 interspersed with many unicellular glands and their secretions, which are seen escaping 

 to the exterior. It rests on a thin basement-membrane, which separates it from the 

 circular muscle-layer. Both this latter layer and the succeeding longitudinal layer are 

 thin and but feebly developed. 



Ova. — The largest specimen is a female, and the entire space within the 

 longitudinal bo<ly-muscles, where not occupied l)y the gut and its lateral diverticula, or 

 by the proboscis-sheath, is filled with eggs of relatively enormous size (PI. I. fig. 8, Ov.). 

 measuring about 0-4 mm. in diameter. Their nuclei are also large (0"08 mni.-O- 1 mm. 

 in diameter) and contain many refringent globules. 



Pnihoyei.^i-fiheath uikJ Pj'ohosris'. — The prolioscis-sheath 

 is proportionally lai-ge, and is supplied with strong circular 

 muscles. 



The proboscis is relatively very stout, but its armatin-e 



is minute, in accordance with the small size of the whole 



Fifi. 2. — Prosioma uiiiliiicti- animal. The form of the central stylet and its Itasis is repre- 



ium: the functional ^pj^^gj j^ text-fig. 2. The basis measures 0-15 mm. in 



.stylet of the proboscis, , , mi 



and its basis hii'hlv '(""g'f'i- ihcre are two pockets contaunng reserve stylets to 



magnified. the luuuber of al)out four in each. 



O'l mm. 



