Mandibles (fig. ii, a, 6 and c) narrow with four teeth and the inferior angle produced 

 either in a single tooth or in two smaller teeth: in two specimens the right mandible had the 

 inferior angle terminating in two, the left in one larger tooth. 



Maxillae having the three larger upper unequal spines and the notch beneath these 

 as in D. orthogonia. In the notch two delicate spines are planted as a rule and the inferior 

 slightly projecting part is indistinctly divided into an upper step with three and an under step 

 with five or six spines. (In fig. 1 2 of PI. Ill one of the maxilla of a specimen of this species 

 is represented with only two large upper spines; the other maxilla of the same specimen had 

 the normal number of three spines above the notch). 



Outer maxillae, outline semi-elliptical rather than hemispherical ; not sparingly 

 covered with brisdes. The longest bristles are planted near the middle of the outer margin 

 of the maxilla. 



Cirri. Pedicels and rami of the five posterior pairs are very long; segments much 

 elongated, each bearing four pairs of very long spines and a fifth pair much shorter. Between 

 each pair there is an excessively minute spine — as described by Darwin for D. orthogonia. 



Of the first pair, which is separated by an interval from the second pair, both rami are 

 short and only slightly unequal in length; the number of segments is 6 in the shortest and 7 

 in the longest ramus. Both are paved moderately thickh- with spines as in D. orthogonia. 



Caudal appendages long and narrow, distinctly two jointed, with a number of long 

 hairs or delicate spines at their ends and a few hairs planted here and there (PI. Ill, fig. 13). 



Penis short, thick; terminating in a narrower and curved part bearing a tuft of very 

 delicate hairs. 



This species was taken at : 



Stat. 164. August 20, 1899. Lat. i°42'.5 S., Long. I30°47'.SE. Depth 32 m. Bottom: sand, 

 small stones and shells. About 12 specimens. 



General Remarks. I have some doubt as to -whether I am rioht in considerine this 

 as a species; but as there are full-grown specimens with egg-lamellae in the collection and as 

 these differ in the shape of the valves from D. orthogonia, to which this form in other regards 

 shows great resemblance, I have thought it useful to give a description of it and to consider 

 it as a separate species. I have the impression that several species in this genus have rather 

 fluctuating characters, but it is quite impossible to make out how far the variation or the 

 fluctuation of these characters goes without a very large material of specimens from the same 

 locality as well as from diff"erent places. 



The species is named after Dr. J. Versluys, one of the Zoologists of the scientific staff 

 of H. M. S. "Siboga". 



Forma dubia. 1 have figured on PI. Ill (in fig. 14) another form of Dichelaspis, 

 which is represented by one specimen only. It belongs, no doubt, to the same group of species 

 as D. orthogonia., IVeberi and Versluysi and it shows in many regards great resemblance to 

 D. Versluysi in particular: it has almost the same form — but, as it is at the same time 



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