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PROCEEDINGS OF THE NATIONAL MUSEUM. 



VOL. XXXVI. 



a b 

 Pig. 6. — Acanthoniscus spiniger. 

 First Maxilla, a. Inner lobe. 

 &. Outer lobe. X 77J. 



the abdomen. The outer branch is produced in a long spine, ex- 

 tending half its length beyond the inner posterior, angle of the 



peduncle; in a dorsal view it is in- 

 serted on the inner lateral margin at 

 the anterior angle. 



An anterior view of the head shows 

 the labrum produced on either side 

 so as to extend much beyond the 

 epistome. The inner lamella of the 

 first maxillae carries' two plumose 

 processes. 



Although this specimen does not 

 agree in every respect with the de- 

 scription of Kinahan, I can not but 

 think it is the same species. Kina- 

 han does not mention the small spines 

 placed between the two long spines on 

 the posterior mar- 

 gin of the thoracic 

 segments. He also 

 does not mention the 

 presence of spines on the abdomen, but in his 

 figure of the terminal abdominal segment I think 

 he intended to represent them in the two long 

 lines in the center of his figure. His representa- 

 tion of the uropod does not agree with the specimen I have, but 

 the shape of the terminal abdominal segment is so similar that I 

 am inclined to think that there must be some error in the figure of 

 the uropod. 0 



a Since preparing tlie above description I sent a copy of my figure to Doctor 

 Caiman of the British Museum for comparison with the type. In his answer, 

 just received, he says that he is almost certain that my specimen is Acantho- 

 niscus spiniger. He mentions the fact that in the type-specimen there are 

 two teeth instead of three on the posterior margin of the thoracic segments 

 after the first. On the first segment, the middle tooth is extremely small. On 

 the hinder edge of the head are only two teeth, placed a little in front of, 

 not on, the margin. He also noticed a difference in the shape of the uropod, 

 but thinks this may be due to its being in a slightly different position from 

 my sketch. He very kindly made drawings of the type for me. Although I 

 am aware of these discrepancies, I hesitate to consider my specimen other 

 than Acanthoniscus spiniger when the resemblance is so strong and the locality 

 the same. Moreover the type-specimen is probably a dried specimen and some 

 allowance must be made for change in contour owing to its condition. When 

 Kinahan described it, twelve years after it was collected, it was probably in 

 no better condition than it is now. 



Fig. 7. — Acanthon- 



I S C U S SPINIGER. 



Anterior view of 

 head showing 

 epistome with 



LABRUM. 



