96 DE- "W. T. CALMAN ON A 



endopodite possesses a suture-line running inwards from the outer margin in a corre- 

 sponding position, which looks as though it might be produced by the pressure of the 

 endopodite against the ridge of the exopodite. It is very rare for the endopod of the 

 uropods to show any trace of division into two segments by a suture-blue, and I do not 

 know of any other case among the Caridea. 



The branchial apparatus comprises five pleurobranchiae on the somites of the peraeopods, 

 an arthrobranchia on the third maxilliped, mastigobranchias (epipodites) on the first and 

 second maxillipeds and possibly also on the third (if this be the value of the spinose lobe 

 described above), .and a vestigial podobranch, represented by the simple lobe on the 

 epipodite of the second maxilliped. The branchial formula of Palcemon differs from 

 this by the presence of a pleurobranchia above the third maxilliped and a distinct 

 podobranchia on the second. 



The colour in life is stated to be white. 

 Measurements in millimetres : — 



d. S- 



Total length 51 42-5 



Length of carapace and rostrum 20 17 - 5 



Inner flagellum of antennule (incomplete) ... 28 — 



Second leg 48 § 5 



„ „ merns — ll'O 



,, „ carpus 7"5 



,, „ palm — 1O0 



„ .,, fingers 130 



The characters of this species, as described above, show that it must be referred to 

 the family Palseinonidse as defined by Borradaile *, but its exact position within the 

 family is not so easy to define. Borradaile includes as a subfamily of the Palaemonidse, 

 the Pontoniince (formerly ranked as a distinct family), which are distinguished from most 

 of the Pal&monince by having, among other characters, the rostrum often small and not 

 serrated, the bifurcation of the outer antennular flagellum reduced to a minimum, 

 and the mandible without a palp. In these points the present species agrees, but I do 

 not think that it can be regarded on that account as having any special affinities with 

 the exclusively marine Pontoniince. As a matter of fact, the Palamonince already include 

 one genus, Euryrhynchus, Miers f , which agrees with that here described in the three 

 points of palpless mandibles, reduced and non-serrated rostrum, and freshwater (possibly 

 also subterranean) habitat. Prom Euryrhynchus and all the other Palcemoniuce, however, 

 Typhlocaris differs not only in the suppression of all spines or teeth on the antero-lateral 

 margin of the carapace, but in other characters so important as to suggest that it may 

 be necessary to establish at least a new subfamily for its reception. Chief among these 

 characters are the presence of a pair of suture-lines on the carapace and the undivided 

 distal endite of the maxilla. I am not aware that these characters are paralleled in any 

 of the Caridea, and if, as seems possible, the suture of the carapace be homologous with 



* Ann. Mag. Nat. Hist. (7) xix. p. 472 (1907). 



t See Caiman, Ann. Mag. Nat. Hist. (7) xix. p. 295 (1907). 



