372 THE ANNELIDA POLYCHAETA. 



forms as small Crustacea, spicules of sponges, foraminifers, radiolarians, and 

 diatoms (Mcintosh, Challenger Annehda, 1885, p. 383-385). 



The classification of the cirratulids is not in a wholly satisfactory condition 

 either as to genera or as to species. A revision is much needed that shall be 

 based upon a thorough study of type-species and their development along the 

 lines so well initiated by CauUery and Mesnil. Until this is done the significance 

 or reaUty of certain genera must remain problematical. In the following key 

 the genera are taken up as more commonly conceived. 



Key to Genera. 



a. Without large prehensile tentacles CirratuHnae, subfam. nov. 



b. Only lateral branchial filaments present, these occurring usually on nearly all somites. 



Cirrineris Blainville. 

 bb. Some dorsal filaments or cirri present in addition to the lateral ones. 



c. The dorsal cirri occurring on the first setigerous somite and often on one or more of the follow- 

 ing ones as well Cirratulus Lamarck. 



cc. No dorsal cirri on the first one or more somites, but these present on one to several of the fol- 

 lowing ones Audouinia Quatrefages. 



aa. With large prehensile tentacles (recalling those of the Spionidea). . . . Dodecaceriinae, subfam. nov. 



b. Body with two divisions, an anterior of nine somites and a posterior, of which the first somite 



is twice as long as those of the anterior region and bears different and shorter setae and crochets. 



Cirratulispio Mcintosh. 

 6b. Not so. 



c. Branchiae few in number (one to eight pairs). 



d. Palpi borne on the prostomium; composite setae present. 

 e. Branchiae present on the first metastomial somite. 

 /. First metastomial somite bearing two pairs of branchial filaments. . . .Aarocirrus Grube. 

 ff. First metastomial somite bearing only a single pair of branchiae. 



Ledon Webster and Benedict. 



ee. No branchiae present on the first metastomial somite Macrochaela Grube. 



dd. Palpi borne on the first metastomial somite; setae all simple. Branchiae from four to eight 



pairs Dodecaceria Oersted. 



cc. Branchiae rather numerous. 



d. Acicular setae adorning nearly the entire circumference of the posterior somites. 



Chaelozone Malnigren. 

 dd. Acicular setae not thus encircling the posterior somites. 



e. Acicular setae, either entire or bidcnf ate, occurring in both notopodia and neuropodia. 



CauUerieUa, gen. nov.' 

 ee. Setae all fine, capillary Tharyx Webster and Benedict. 



CiEEiNEEis Blainville. 



Diet. sci. nat., 1828, 57, p. 488; St. Joseph, Ann. .sci. nat., 1894, ser. 5, 17, p. 42; Mesnil and Caullerv, 



Ann. Univ. Lyon, 1898, p. 110. 

 Cirrhineris Quatrefages, Hist. nat. anneles, 1865, 1, p. 462. 

 Labranda Kinberg, Ofvers. K. vet. akad. Forh., 1865, no. 4, p. 255. 



1 Genotyjae, C. I'iridis (Langerhans) (Cirratulus viridis Langerhans). Including also Helerocirrus 

 ccj.ut-csncis St. Joseph, Cirrahdus jragilis Leidy, and perhaps Cirratulus bioculatus Keferstein. 



