30 Dr. W, T. Caiman on some Genera 



following notes. A proper revision of tlie genera would 

 demand the study of much more material than is at my 

 disposal, and for this reason I have confined my examination 

 to characters M'hich have already been employed tor systematic 

 purposes by previous authors. 



The limits of the family cannot be said to be satisfactorily 

 defined at present. On the one hand, the recognition of the 

 fact that the legs of the first pair in many Pandalidaj are not 

 "simple," but microscopically chelate, renders it hard to 

 define that family so as to exclude the Hi|)polytid genus 

 Cryptochtles, in which the chelae of these limbs are stated to 

 be " minute.''^ On the other hand, the boundary between the 

 Hippolytidje and Alplieidae is so vaguely marked that even 

 Couti^re, in his elaborate monograph of the latter family, is 

 unable to decide as to the proper position of certain genera, 

 such as Ogyris. Ortmann (Bronn's Thier-Reich, Crust. 

 ii. p. 1130) has separated a group of genera to form the 

 family Latreutidaj, characterized by the absence of the 

 incisor-process * of the mandible. It is impossible, however, 

 to retain this arrangement, since the genus Nauticxris, 

 which Ortmann refers to the Latreutidas, is certainly closely 

 allied to Saron, as, indeed, Thallwitz pointed out in 

 establishing the latter genus. The genus Lysmata is referred 

 by several recent writers to the Processidie (Nikidse), but it 

 seems to be undoubtedly connected with the Latrcutid group 

 through Stimpson's Ilippolysmata. The settlement of such 

 questions, however, must wait for a future reconsideration of 

 the wjiole classification of the Caridea. 



The following is a partial and provisional synopsis of the 

 genera usually referred to the family. The names of those 

 genera of which I have seen no specimens are enclosed 

 within square brackets : — 



A . Arthrobrancliise are present at the bases of 

 ihe tirst four pairs of peraeopods. Man- 

 dible with palp. More than seven seg- 

 ments in carpus of second peryeopods. 



a. Movable spine at base of uropods. 



a. Mandible with incisor-process Saron, Thailwitz. 



j3. Mandible without incisor-process . . Nuuticaris, Spence Bate. 



b. No movable spine at base of uropods. 



a. Mandible with incisor-process Merhippolyle, Sp. Bate. 



fi. Mandible without incisor-process . . IWhippulyte, LJorradaile. 



* I have employed the terra " incisor-prose.ss " for the distal division 

 of the mandible. It is naturally suorgested by " molar-process " and is a 

 little more detinile than " cutting--edge," while requiring le.-s explanation 

 than " psalistoma." 





