12 R. KIRKPATRICK. 



like spicules of Melonanchora, in which, however, three opposite pairs of teeth have 

 become united. 



Hoplakithara dendyi is remarkable for its exotyles with very large spirted heads ; 

 this species also has fimbriated placocheles. 



The spathulate bipocilla occurring in two new species of lophon are worthy of 

 mention. A bipocillum of this kind occurs, also, outside the genus lophon, viz., in a 

 new species of Myxilla. 



Geographical distribution. As might have been anticipated, a large proportion of 

 the known forms have already been recorded from the Southern Hemisphere. 



Of the twenty known species, fourteen have been recorded from the South Atlantic 

 or Indian Ocean, or from the southern portion of the east and west coasts of South 

 America. Only two species have been previously recorded from the Antarctic region, 

 viz., lophon radiatus Topsent and Gellius rudis Topsent, both obtained by the 

 ' Belgica ' expedition from the opposite quadrant of the Antarctic circle. 



Of four species which have been recorded from the Arctic region, one, viz., 

 Sphaerotylus capitatus (Vosmaer), has never been obtained from any intermediate station. 

 Artemisina apollinis (R. & D.), which was obtained by the ' Challenger ' from Kerguelen 

 Island, has been recorded by Lundbeck from off Greenland. Stylocordyla borealis 

 (Loven), recorded from the North Sea, and occurring also in the Antarctic, has been 

 obtained from several intermediate localities. Of considerable interest is the occurrence 

 of Esperiopsis villosa Carter, a form frequently recorded from high northern latitudes, 

 but only from one intermediate station, viz., in deep water off the Azores. 



Classification. The classification of the main groups adopted here is that of Dendy 

 (6. p. 60, 134). Deudy divides the Order Tetraxonida into two grades, Tetractinellida 

 and Monaxonellida, and the latter grade into two sub-orders, Astromonaxonellida and 

 Sigmatomouaxonellida. The use of the last two names implies the theory of the 

 relationship of these sub-orders with the astrophorus and sigmatophorous Tetracti- 

 nellida respectively. 



The divisions Clavulida and Aciculida (Topsent) of the Astromonaxonellida 

 (Hadromerina pars Topsent) are adopted ; so likewise is Lundbeck's division of the 

 Desmacidonidae (Poeciloscleridae Topsent) into two sub-families, Mycalinae and 

 Ectyoninae, and of the Mycalinae into two groups, Mycaleae and Myxilleae. 



A preliminary report giving descriptions of new genera and species has been 

 published in the Ann. Mag. Nat. Hist. (7), vol. xx., pp. 271 ft seq., Sept. 1907. 



Below is a list of species of Monaxonellida : 



GRADE MONAXONELLIDA DENDY. 

 I. Sub-order ASTROMONAXONELLIDA Dendy. 

 I. Tribe CLAVULIDA Vosmaer. 



i. Family Spirastrellidae Ridley and Dendy. 



Latruncul ia apical is Ridley and Dendy var. biformis var. n. 

 LatruncttUa apical is Ridley and Dendy var. lasalis var. n. 



