NO. 1580. NEW SPECIES OF CALIOINjE— WILSON. 611 



and its near relatives in having the genital segment ''girded with a 

 nienibraiioiis wing and the tail (really the abdomen) furnished with 

 two elongate, retro vert wings which are in the form of a half moon." 



Heller records the finding of the parasite on a new host in the 

 Indian Ocean, but makes not attempt at a description. 



Basset t-Smith, the most recent authorit}^, gives the following 

 genus diagnosis, })resinnably made u}) from Steenstrup and Liitken's 

 text and figures: 



Carapac(> rounded, scutiform. Frontal border with lunulae. First and fourth pairs 

 of thoracic limbs uniramose, second and third biramose. Genital segment of large 

 size, covered over by two dorsal plates; also with two elongated flattened processes 

 projecting backwards from the posterior l)order and origin of abdominal portion, 

 which latter is Inarticulate, terminating in two small caudal plates. (1899, p. 445.) 



There are at least five serious errors in this diagnosis, l:)rief as it 

 is, besides some equally serious omissions. 



The genital segment is not "covered over" by anything; its 

 dorsal surface is uncovered except at the posterior end where the 

 abdominal wings overlap it somewhat. Furthermore the covering 

 of its ventral surface cannot be called "plates;" they are rather 

 membranous wings like those on the abtlomen, as Steenstrup and 

 Liitken call them. The most noticeable thing about them is that 

 they are turned up dorsally at the edges in a perfect saucer shape, 

 the genital segment lying in the bottom of the saucer. Nothing is 

 said of this by any of the previous authors. 



Again the "elongated flattened processes projecting backwards" 

 are a part of the ventral wings and not a portion of the segment 

 itself, as can be plainly seen in Steenstrup and Liitken's figure as 

 well as in those here given. Their size, their shape, and above all 

 their attachment prove this beyond a doubt. 



The genital segment of the present species does have two flat- 

 tened processes, but they are very short instead of elongate, ventral 

 instead of dorsal, and they are not mentioned at all by Steenstrup 

 and Liitken. In their preserved material, however, these tiny proc- 

 esses could have been easily overlooked. 



Another error is in the statement that the abdomen is "biarticu- 

 late." Steenstrup and Liitken neither in their figures nor in their 

 text give it as such; but they make no definite statement with refer- 

 ence to it. In their figure, however, as in the present species it is 

 certainly one-jointed. 



And, lastly, Bassett-Smith's diagnosis neglects to notice the large 

 wings on either side of the abdomen, which are one of the chief char- 

 acteristics of the genus. 



Steenstrup and Liitken speak in their species description of the 

 wings on the genital segment as "a thin marginal border, consider- 

 ably widened posteriorly." This, taken in connection with the fact 



