104 R. C. PUNNETT. 



The most marked point of difference between C. aliena and the rest of the genus 

 lies in the relative positions of mouth and brain. In all the other species whose anatomy 

 has been described the mouth lies behind the brain, and usually some distance behind. 

 The structure of the epithelium with its double layer of nuclei is more complex than in 

 the rest of the genus. In the presence of an inner circular muscle layer C. aliena resembles 

 C. signata and differs from the other species of Cephalothrix. The great thickness of the 

 basement membrane also is unusual. Moreover to judge by the figures in Burger's Monograph 

 (Taf II.) the i hynchocoelom is less spacious and the blood vessels considerably more so than 

 is usually the case. 



2. Eupolia hemprichi (Ehrenberg, 1831). (PI. IV. figs. 2, 3.) 



Syn. Nemertes hemprichi, Ehrenberg, Symbolae Physicae, 1831. 



Eupolia brocki. Burger, Zeit. f wiss. Zool., 1890. 



Eupolia hemprichi. Burger, Naples Monograph, 1895. 



Eupolia hemprichi, Punnett, Willey's Zool. Results, Pt. v., 1900. 



Locality. Found sparsely on every reef 



Several specimens of this common and widely-distributed species were obtained from the 

 reefs both in the Maldive and the Laccadive Islands. 



The size after preservation varied from 6 5 cm. to 104 cm. in length. The last-mentioned 

 specimen is larger than any other yet recorded. The following note was made on the living 

 worm by Mr Stanley Gardiner : " Length when obtained out of a hole in the rock of the reef- 

 fiat .5 ft. 6 in. (= 167 6 cm.). Black streak down centre of back and same transverse behind 

 head.' These markings become brown after preservation. There was in this specimen also a 

 pigment fleck on the tip of the head and further a ventral line of about the same width 

 as the dorsal extending along the whole length to the collar just behind the mouth. Here, 

 however, it is much thinned (PL IV. fig. 2), and the collar is also incomplete ventrally. In 

 markings as well as in size this specimen is intermediate between the figures which Burger 

 gives of E. brocki (loc. cit. 1890, Taf I. fig. 10) and of E. mediolineata (Zool. Jahr. Bd. 7, 

 Abt. f Syst. Taf VIII. fig. 1). The thickness of the dorsal and ventral lines and also of 

 the transverse one is exceedingly variable. In one case the line may be at least one-third 

 of the body-width, whilst in another it is exceedingly fine. Sometimes again the dorsal 

 stripe is the broader of the two, whilst in others the ventral exceeds the dorsal in width. 

 Such considerations render it not unlikely that the species described by Burger as 

 E. mediolineata may be merely a local variety of E. hemprichi. The species has a wide 

 range, extending from New Britain in the East Pacific, acro,ss the Indian Ocean to the 

 Red Sea. 



In a previous paper I mentioned that the excretory system in a specimen of this 

 species (Punnett, 1900, loc. cit.) was not provided with ducts. This led me to make sections 

 right through this region in a specimen from the Maldives. The result was a confirmation 

 of the previous statement that the excretory system is here unprovided with ducts opening 

 to the exterior. 



3. Eupolia indica, n. sp. (PI. IV. figs. 8, 12, 13, 14.) 

 Locality. Hulule, Male atoll, Maldive Is. From reef. 



