608 PROCEEDINGS OF THE yATIONAL MUSEUM. vol.41. 



CLASSIFICATION. 



None of the new species contained in this collection can be said to 

 throw much new light on the problems of Cumacean classification. 

 In Oxyurostylis smithi the simply pointed apex of the telson, without 

 apical spines, calls attention once more to the impossibilit}^ of basing 

 the distuiction between the families Diastylidne and Lampropidse on 

 the presence in the former of a pair, and in the latter of three or more, 

 apical spines. The species described as Colurostylis (?) occidentalis 

 presents several remarkable characters, and, whether it is rightly 

 assigned to the genus Colurostylis or not, it joins with the type of that 

 genus in breaking down the barrier between the Diastylidas and 

 Pseudocumidae. The discover)^ that the male of Lejptocuma has only 

 three pairs of pleopods perhaps points the way toward a union of 

 the Bodotriidse (including Vauntompsoniida?) and the Leuconidse. 

 It is of course possible, as I have elsewhere pointed out,^ to base on 

 facts such as these an argument for the opposite course of action, and, 

 instead of reducing the number of families, to increase it very greatly. 

 A step in this direction has recently been taken b}^ ]\Ir. Stebbing ^ in 

 establishing a new family Dicidae. In the paper quoted above, which 

 had passed out of my hands before I saw that of ^h. Stebbing, al- 

 though it was not actually published until later, I have described 

 species that divide among them some of the chief characters used to 

 define the genus Die and the family Dicidae. Thus Diastylis jlstu- 

 laris has a similar form of telson, and the species of Gynodiastylis have 

 no pleopods in the male sex; while Doctor Zimmer had previously 

 figured, in Leptostylis thileniusi,^ a form of third maxilliped which, in 

 the great expansion of the ischial, or third, segment, resembles that 

 of Die more than that of any other Cumacean. Whether or not the 

 famU}'" Dicidae may afterwards find a place in the classification, its 

 acceptance at present would require to be balanced by the creation of 

 a considerable number of additional families for genera now included 

 in the Diastylidae, and for this, it seems to me, the time is not yet ripe. 

 Every extensive collection of Cumacea recently examined from tropi- 

 cal and southern seas has yielded species presenting novel and unex- 

 pected combinations of characters, and there is no reason to believe 

 that the supply is approaching exhaustion. For the present, there- 

 fore, it seems advisable to avoid, as far as possible, establishing new 

 systematic divisions. 



SYSTEMATIC NOTES AND DESCRIPTIONS OF NEW SPECIES. 



In the following descriptions "total length" is to be understood as 

 includmg the telson (when distinct), but not the uropods. The "post- 

 anal" region of the telson is measured from the upper posterior mar- 



1 Trans. Zool. Soc., vol. 18, 1911, p. 343. 



2 Ann. South ^Urican Mus., vol. 0, 1910, p. 415. 



3 Zool. Jalirb., Abth. Syst., vol. 17, 1902, p. 442, fig. Q. 



