AMPHIPORUS SPEOTABILIS. 161 



Synonyms. 



1846. Cerebratulus spectabilis, De Quatrefages. Ann. des sc. nat., 3 me ser., Zool., p. 219, tab. 10, f. 7. 



1849 - „ „ Ibid. Voyage en Sicilie, vol. ii, p. 131, pi. 17, f. 12 and 13. 



1850. Nemertes spectabilis, Diesing. Syst. Helm., vol. i, p. 272. 



1852. Cerebratulus spectabilis, Max Schultze. Zeitsch. f. wiss. Zool., Bd. iv, p. 183. 



1861. „ „ Grube. Ein Ausflug nach Triest, &c, pp. 80 and 129. 



1862. Nemertes spectabilis, Diesing. Revision der Turbell., p. 299. 



„ Borlasia splendida, Keferstein. Zeitsch. f. wiss. Zool., Bd. xii, p. 59, taf. v, f. 10—18. 



1863. Ptychodes splendida, Diesing. Nachtrage zur Revis. der Turb., p. 12. 



1864. Cerebratulus spectabilis, Grube. Die Insel Lnssin u. ihre Meeresf., p. 94. 



1869. Cerebratulus (Ommatoplea) spectabilis, Mcintosh. Trans. Roy. Soc. Edinb., vol. xxv, pt. ii, 



pp. 342 and 355. 



Habitat. — Dredged off St. Peter Port, Guernsey, at a depth of 18 — 20 fathoms, in a fissure 

 of Eschara foliacea. Sicily, the Adriatic and St. Vaast-la-Hougue ; generally in the crevices 

 of shells. 



Body rather more than three inches in length, and about a fifth of an inch in breadth, flat- 

 tened ; dilating rather abruptly behind the snout, and again diminishing towards the tail. The 

 margins are thin. 



Colour brownish, with six longitudinal brown stripes on the dorsum, and five pale inter- 

 mediate lines. The two bands on each side of the central line are somewhat dark in colour, 

 wide in front, narrow and somewhat closely applied posteriorly. The two adjoining brown belts 

 become considerably wider towards the tail. Besides the foregoing there is also a marginal brown 

 stripe, which is somewhat wider posteriorly. The tip and edges of the snout are pale, the four 

 central brown bands of the dorsum being continued thereon, the two lateral becoming indistinct 

 over the pigmentary region, the two central almost reaching the tip of the snout. All the four 

 stripes are much narrowed and more closely approximated after passing the cephalic furrows, 

 and the two lateral are in addition bent inwards towards the middle line at the latter. 

 The under surface has a uniform pinkish colour, slightly marked within each border by a reddish 

 coloration from the vessel. 



Head narrower than the rest of the body, somewhat conical, defined posteriorly by a very 

 distinct notch on each side. The region assumes various shapes according to the motions of the 

 animal, sometimes presenting a blunt tip with a notch in the centre and almost cylindrical, at 

 others a dilated tip and a constricted posterior portion. In the recently captured animal the eye- 

 specks are not very evident on the dorsum, but after it has been blanched by captivity, they 

 are observed to form two rows on each side, the central having about ten eye-specks, and the 

 lateral a larger number. The former are best seen on the dorsal, the latter on the ventral surface, 

 or from the side, and they proceed further forward than the central, indeed, almost to the tip of 

 the snout. In the inner rows the eyes are nearly equal in size, while in the outer there are some 

 larger ones towards the front. 



Cephalic furrows. — Prom the notch, which on each side marks the posterior boundary of the 

 snout, a well- marked furrow proceeds inwards and backwards, and is joined by eight or nine deep 

 grooves which occupy the slightly dilated region immediately in front of the oblique furrow. 

 These accessory grooves have in general a longitudinal direction, but they are curved in various 



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