On a Bhawania-specimen, a contribution to our knowledge of the Chrysopetalidae

Amidst sponges, recently collected by my friend Mr. P. J. Buitendijk in the bay of Batavia, I met with a Polychaeteworm, obviously belonging to the genus Bhawania of Schmarda 1). Though I cannot give full information about its structure, because I had only a single specimen at my disposal with its head so far withdrawn that it was quite invisible, nevertheless I think the present communication not without interest, since Schmarda’s description is rather incomplete and there still reigns a good deal of uncertainty about the affinity of the paleae-bearing Polychaetae. It is a slender, flattened worm, measuring 25 mm. in length and 1½ mm. in breadth; the body is only slightly tapering at its anal extremity and has about 175 segments. Its colour is yellowish gray with a somewhat paler dorsal border and a median row of black spots at the ventral side; moreover there is a couple of black patches at the base of each foot, forming along the sides of the body a narrow dark band. The dorsum is entirely covered by the paleae (fig. 1), which are arranged in slightly bent transverse rows, with the concavity directed forward; this concavity increases towards the head and on the anterior segments the rows nearly have the shape of a circle. Each row consists of a left and a right half, each containing in the middle of the body 20 paleae; the median ones of both sides are partly stretching over each other in the middle of the back. The paleae differ somewhat in size in different regions of the body, and in the same row the lateral ones are the longest and extend a little beyond the others. As rightly stated by Ehlers 1) these paleae show a great resemblance with the scales of the butterfly-wing; they consist (figs. 2 and 3) of a shaft, entirely hidden in the dorsum, and a broad distal division. The shaft, measuring about a third of the total length of the bristle, is faintly knee-like bent and becomes somewhat broader in its upper beneath the cuticula lying portion.