I ■■ 



line, although those on the right side were slightly more developed than those on the left. 



rhe directives hardly projected beyond the lower border of the stomatodaeum, and on either 



side of tin ut were two mesenteries, apparentlj of the sterile type, which 



tended to about li;ilt wa\ between the lowei border of the stomatodaeum 



and the aboral pole. Next on either si. Ie came a long mesentery, extending 



almost to the aboral pole and bearing each an acontium; these, the fourth 



iuple of protocnemes 1 take to be the telocnemes. < >f the deuterocnen 



only two were present on either side of the median line: one of these 

 xii. • 



ig the was of about the same length as the second and third protocnemes and 



like these apparenth of the sterile type, while the other hardly projected 



tentacles in .i larva * * ' ' ' ' J 



beyond the lower 1 «order ot the stomatodaeum and had not yet developed 

 a mesenterial filament. 

 The locality from which . /. sióoga was obtained seems to preclude any probability of 

 its identity with ./. alóida. But in addition its distinctness is shown by the earlier development 

 of the acontia, the youngesl example of A. alóida described by van Beneden not showing them, 

 although it is in a slightly more advanced stage of development than the examples of A. sióoga, 

 possessing thirteen mesenteries and six labial tentacles as against twelve mesenteries and five 

 labial tentacles. Another difference exists in the length of the stomatodaeum, which is considerably 

 longer in A. siöoga than in . I. alóida, the mesenteries of the former species thereby appearing 

 somewhat shorter. 



Genus Dactylactis van Beneden. 



Synonym: Dactylactis van Beneden, 1898. 



Larval Arachnactidae in which the marginal tentacles in earlv stages are not very much 

 longer than the column and are continuous on their aboral surface with the column wall, nol 

 being separated from it by a groove. Their ectoderm shows more or less distinctly a differentiation 

 into four hands, that of the oral and aboral surfaces being richly provided with nematocysts, 

 while these structures are almost lacking on the lateral surfaces; the median tentacle of the 

 developes early. The oral tentacles develope earlv. Column ovoid, or, in earlv stages, 

 ii al. I he directive mesenteries are prolonged some distance below the lower border of the 

 stomatodaeum and acontia are borne by the mesenteries of the fourth and sixth couples. 



9. Dactylactis malayensis n. sp. 



Stat. 172. Gi ei [sland, anchorage between tliis island and Ceram-Laut. Plankton. Numerous 

 examp] 

 tat. 185. Manipa Strait. HEN tical net, [536 m. to surface. 1 ex. 



' )f this form there were numer< imples, the majority of which, however, had been 



■ d in alcohol and were considerably distorted and shrunken. A number, fortunately, were 

 llently preserved in }".<„ formalin and these alom- were used for study. 

 all the body was ovoid in form PI. I. fig. \\\ and surmounted by a corona ot 



42 



