1905.] SPECIES OF WORM FROM THE RED SEA. 561 



this septum is not quite so strongly developed as those which lie 

 in front. The last hearts lie in segment xiii. The nepliridia are 

 obvious in segment xv. 



The sj^ermathecce, which open in line with the male pores, i. e. 

 with seta h of Michaelsen's scheme*, have a single diverticulum of 

 about half the length of the pouch itself. Their pores are sitiaated 

 between segments vii./viii. and viii./ix. 



The spermiducal glands, like those of some, but not every, species 

 of the genus, possess a distinct duct separable from the glandular 

 and also tubular region by a constriction and by its nacreous 

 appearance due to the strong muscular coat. The glandular part is 

 fully six times as long as the muscular duct. The duct in the 

 fully mature is curved into a horseshoe- shape. It is of uniform 

 thickness though out, and does not increase in diameter towards 

 the external pore. 



For the purposes of an easier comparison with other species I 

 append a definition of this new Pontodrilus, which I propose to 

 name after Mr. Crossland. 



Pontodrilus crosslandi, sp. n. (Text-fig. 78.) 



Length about 100 mm. Prostomium epicheilous (^-5). Setce 

 2)aired rather distant ; distance a-b less than c-d. Clitellum. xiii- 

 xviii. Male pores {on xviii.) and sperm.athecal pores {yii.jviii., 

 viii.jix^ in line with seta b. Papilla} paired on intersegmental 

 areas xiii./xiv., xiv./xv. Last thickened intersegmental septum 

 xiii./xiv. Last hearts in xiii. Spermathecce with single diverticidum 

 half the length of the j)ouch. Spermidtical glands with distirict 

 muscular duct. — Hah. Shores of Khor Dongola, Red Sea. 



In view of the cutting of the Suez Canal and the alleged and 

 consequent migration of the Mediterranean fauna eastwards and 

 of eastern additions to the same t, it is important to note that the 

 species Pontodrilus crosslandi is by no means a variant of, or most 

 nearly related to, the Mediterranean P. littoralis. It comes 

 nearest, as I am inclined to think, to P. laccadivensis and P. 

 matsushimensis var. chathamiana by reason of its anteclitellian 

 papillae, unknown in other species. It lacks the papillae following 

 the male pores, which are so general in Pontodrilus. 



To emphasise the likenesses and also the difierences between 

 P. crosslandi and P. laccadivensis I add a figure of the latter 

 (text-fig, 79, p, 560) for purposes of comparison. This species has 

 not yet been figured, though its essential characters have been 

 described +. 



* Oligochaeta, in ' Das ThieiTCich,' 10 Lief. (Berlin, 1900). 

 t E. A. Smith in P. Z. S. 1891, p. 396. 



X Beddai\d in 'The Fauna and Geography of the MaMive and Laccadive Archipe- 

 lagoes,' vol. iv. pt. iv. p. 374 



