FEOM THE CAPE OF GOOD HOPE. 261 



The head is long, and the eyes are placed at the corners of a wide trapezium. 



The paragnaths of the distal or maxillary division of the prohoscis are much smaller 

 and feebler than those of the proximal or oral division. 



Length 95 mm. ; width in front (gradually tapering backwards) is 4 mm. Avithout 

 tlie feet, 6 mm. inclusive measurement. 



Locality. Eorty-one atokous specimens taken among rocks at Green Point, Table 

 Bay, in November 1896 ; twelve epitokous examples taken in the mud on the mud- 

 banks of the Knysna lagoon. 



In the structure of the parapodia and their armature this species apparently does not 

 differ from Grube's Nereis brevicirris * from St. Paul, but with regard to the arrange- 

 ment of paragnaths, there is, in the latter species, a group of three teeth of the order V 

 placed in a triangle behind the confluent monostich of VI. In spite of this apparent 

 difference, which is not great in view of the frequency of meristic variations and of the 

 common occurrence of supernumerary teeth, I think Grube's species would be more 

 suitjibly entitled Neanthes latipalpa brevicirris. 



Another representative of the same specific group was collected in Ceylon by 

 Mr. L. A. Borradaile, who has added the specimen to the material of the British Museum. 



11. Neanthes capensis, sp. n. (Plate 13. fig. 10 and Plate 14. figs. 9 & 10.) 



A number of small Nereids taken in company with Platynereis striata off Woodstock 

 beach have all groups of paragnaths represented in the proboscis by conic;al sclerites, 

 and therefore belong to Kinberg's genus Neanthes. 



The third pair of tentacular cirri stretch over 4-8 segments. There is a faint 

 moniliform pattern along the centre of the back over the dorsal vessel, which serves to 

 distinguish them, when the proboscis is not exserted, from Fluti/nerels striata. The 

 lisrules of the feet are rounded in front and become conical behind. 



An incomplete specimen had 63 segments ; length 31 mm., width over all 3-5 ram. 

 The length of the antennae seems to vary somewhat from about half the length of the 

 prostomium to more than half this length. 



The paragnaths of group VI are disposed in an acervus, and the species therefore 

 falls into line with N. acuminata, Ehlers, and N. crucifera, Grube. 



12. Mastigoneiieis opeuta. (Plate 13. figs. 11 & 12 and Plate 14. figs. 7-8 a, b.) 



Nereis uperta, Stimpson, 1855, Proc. Acad. Pliilad. vii. p. 392. 



Mastiyunereis latipalpa, Schmarda, 18(51, Neuc wirbellose Thicrc, ii. 



Mastiyonereis retrudentata (Quatrefagcs, 18(J5, Hist. Nat. Anucl. i. p. 557) ; cf. Marenzellcr, 1888, 

 Polychaten der Angra Pequeua-Bucht, p. 7. 



The collection comprises atokous and epitokous forms, with transitions from one 

 condition to the other. The occurrence of epitoky is a fact of great bionomic interest, 

 l)ut from a strictly systematic standpoint an epitokous Annelid, although it has 

 achieved its highest development, is of no more practical use for diagnosis than tlie 

 same worm in the atokous condition. That is to say, the substitution of reniform seta? 



• Unibe, A. E., " Anuclidcu," Novara-Kcise, Zool. Bd. ii. (.Vienna, 1S«7), p. It", Taf. ii. fig. 2. 



