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the Nauplii ready for hatching; these larvae showed no trace of pigment in the eyes. The 

 greatest diameter of the egg is 0,22 mm. 



The specimens taken by the "Siboga" were attached to stones and shells. 



This species was collected at : 



Stat. 260. December, 16 and 18, 1899. Lat. 5° 36'.5 S., Long. I32°55'.2E. Depth 90 m. Bottom: 

 sand, coral and shells. [2,3 miles N. 63' W. from the north point of Niihu Jaan, 

 Key Islands]. 



General Remarks. This is an interesting species, forming a link between the species 

 with quite normal rami in the 5"^ and 6''> cirri and those in which the inner ramus of these 

 cirri is quite rudimentary. The "Siboga" took four large and several smaller specimens of this 

 species. I think it worth while to note, that the orifice of the capitulum, which is a narrow slit 

 in the full-grown specimens, is broad and nearly circular in the small. In some regards this 

 species seems to resemble A. xenopJiorac Annandale — a figure of that species might at once 

 settle this question '. 



3. Alcpas lithotryac n. sp. PI. IX, fig. 5—8'. 



Capitulum hardly distinct from peduncle, globular, with low and indistinct carinal crest. 

 Orifice not protuberant, short and narrow. No scuta; the place these should occupy indicated 

 as smooth patches of oval shape. The cirri of the 5"^ and 6''' pair shorter than the foregoing 

 ones. Inner ramus of the cirri of the 5''^ and 6'^^ pair slightly shorter than the outer rami. 



The capitulum of this species in some of the specimens almost insensibly slopes into 

 the peduncle (PI. IX, fig. 5), in others it is distinctly separated from the peduncle by a contraction. 

 Its shape is globular, with the carinal margin strongly bowed; the orifice is narrow and relatively 

 short, and is straight seen from the side ; the occludent border beneath or behind the orifice is 

 slightly convex. Along the carinal margin is seen a very low crest which continues along the 

 peduncle. There is a reticulation of delicate striae all over the surface and deeper wrinkles 

 occur near the orifice, being placed at right angles to its main axis. Neither striae nor wrinkles 

 occur at a place of oval shape under or in front of the orifice, on both sides of the capitulum : 

 these smooth places or patches probably represent the so-called horny scuta of some of the 

 other species. 



The peduncle is very short, its general shape is cylindrical. The surface is indistinctly 

 ringed; on the one side (in the specimen figured, the left) the base of the peduncle forms a 

 chitinous e.xpansion with which the little body is attached to the surface of one of the valves 

 of the Lithotrya. 



Size. The length of the capitulum and the peduncle together is, in the largest specimen, 

 about 4,5 mm., the length of the peduncle being about i mm. The other specimens are considerably 

 smaller; the largest has been used for the description of the shape of the capitulum, as well 

 as of the structure of the animal's body. It was not furnished with egg-lamellae, but to judge 

 from the state of development of the ovary, it was full-grown, mature or nearly so. 



' .-V figure is given in "Illustrations of the Zoology of the R. 1. M. S. S. Investigator", Calcutta, 1907. I think Ann.\ndale's 

 A. xenophorae and my A. intermedia are different species. (Note added during press). 



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