458 W. F. L A NC HESTER. 



make it more than probable that, in the absence of definite evidence to the contrary in 

 Claus' work, his specimen was armed with these spines; and thirdly, because similar spines 

 are present "in the other example of an Alimerichthus described below. 



Loc. North Male Atoll, Maldives, 27—35 f. 



5. Alimerichthus unidens sp. no v. 



A single example from South Nilandu Atoll, 19 — 25/. 



This species agrees in so many points Avith the preceding that, on a first examination, 

 I was inclined to consider them as identical. The carapace has the same arrangement of 

 primary and secondary spines, and a similar pyramidal support for the dorsal spine ; the abdomen 

 has spines on the postero-lateral angles, and submedians on the 6th segment; the uropods 

 and telson are exactly similar. Two conspicuous differences mark the species ofi' very clearly. 

 Firstly, its size; the greatest length of the animal being only 12-5 mm., it is obvious that, 

 were it specifically identical with Alimer. pyramidalis, it should represent an earlier stage in 

 the development of that species, a stage in which the uropods should be but little developed, 

 and the telson wider in proportion to its length, as is the case even in a specimen 15'5 mm. 

 long figured by Brooks {I.e. PL IX. Fig. 3) ; seeing, however, that it is in the same stage, 

 structurally, as the 17 mm. larva described, and as the 16 — 18 mm. larva of Claus, it is 

 extremely unlikely that we are dealing here with that species ; rather we must believe that 

 we have a different larval species in which the structural advances correspond to a smaller 

 advance in size than in Alimer. pyramidalis. This view is strengthened by the second 

 difference to be noted, namely, that the dactyl of the raptorial claw is armed with one 

 fully -developed spine in addition to the terminal one, and possesses rudiments, proximally 

 to this, of only two others; pointing to its connection with an adult species of Squilla in 

 which there are fewer spines on the dactyl than in the adult of Alimer. pyramidalis. 



6. Coroniderichthus bitubercidatus Hansen. 



Isopoden, Cumaceen, u. Stomatopoden der Plankton Expedition, p. 83 (1895). Erichthus 

 armutus Claus (pars), Abh. d. Icon. Ges. Wiss. Gottingen, XVI. PI. IV. Figs. 15—15' (1872). 



One specimen from Suvadiva Atoll, Maldive Is. 44/., which accords closely with Claus' 

 figures. There is a secondary tooth between the submedians and sublaterals of Hansen, 

 representing his intermediate ; in addition, and these are not figured by Claus, are two small 

 spines, one at the base of the sublaterals, the other at the base of the laterals. There are 

 three rudimentary teeth under the skin on the dactyl of the raptorial claw, and two sub- 

 median spines on the 6th abdominal segment. 



[Note. When this paper was written I had not seen the description of two varieties 

 by Dr de Man in a recent paper, "Die von Herrn Prof Kukenthal...gesam. Dekap. u. 

 Stomatopoden," 1902. Dr de Man's var. affinis is coextensive with my var. segregakis, his 

 name having priority, but presents certain differences: similarly his var. confinis seems to be 

 coextensive with var. anancyrus, though again presenting differences. The reader should refer 

 to p. 912 of the above-cited work. Dr de Man agrees with me in considering var. affinis 

 as transitional to var. glabrous.^ 



