328 On Araclinida &c. from Funafuti and Rotuma. 



Family Cylindrodesmidse, nom. nov. 

 (=IIaplosomidcB, Silvestri ; Haplodesmid(s, Cook.) 



Genus Cylindrodesmus, Poc. 



Cylmdrodesmus,VQCOc\, Proc. Zool. Soc. 1888, pp. 558-560. 

 Haplosoma, Verhoeff, Zool. Anzeiger, xvii. p. 8, 1894 (nom. prgeocc). 

 Haplodesmus, Cook, Ann. New "York Acad. ix. p. 4. 



A re-examination of the type species of Cylindrodesmus^ 

 namely hirsutus^ from Christmas Island, has failed to reveal 

 to me any satisfactory character by which this genus can be 

 distinguished from the later-described form Haplodesmus, 

 Cook {= Haplosoma, Yerh.). An apparent discrepancy lies, 

 it is true, in the fact that VerhoetF assigns nineteen body- 

 segments to his form, while twenty were, by implication, 

 assigned by me to Cylindrodesmus. As a matter of fact, the 

 adult male of the latter has nineteen segments and the adult 

 female twenty and thirty-one pairs of legs. But the female 

 of Herr Verhoeff's species is said to resemble the male in this 

 character. I venture to think, however, that the presence of 

 nineteen segments in the female of Struhelli, the type of 

 Haplodesmus, is due to the immaturity of the specimens 

 examined, an opinion which is borne out by the opening words 

 of Verhoeff's specific diagnosis : — " Korper der Mannchen 

 hellbraun, der Weibchen weisslich." 



In the specimens of the two species that I have examined 

 the adult female is the same pale brown tint as the adult 

 male, while the immature female is much paler. 



It may be added that, both in the figure and description of 

 Mrsuius, the prominence of the labrum is exaggerated. 



The cuticle of hirsutus is thickly covered with short hairs, 

 amongst which are scattered here and there long bristles or 

 short cylindrical blunt-tipped bristles, apparently repre- 

 senting the basal segment of the longer setae, which persist 

 especially along the hinder border of the segments or at the 

 sides, where there is protection from rubbing. The sternal 

 surfaces are coxiform, being deeply grooved transversely and 

 longitudinally. 



In the legs the trochanters (" femora," Verhoeff ) are about 

 twice the length of the coxae and about two thirds the length 

 of the femora ("tibiae," Verhoeff); the patellae and tibiae 

 are very short and subequal, taken together shorter than the 

 femur ; the tarsus is the longest segment, being longer than 

 the femur; the proportion varies, however, a little in different 

 parts of the body. The anal sternite has two prominent 

 angular tubercles, from each of which a long bristle emerges. 



