ir aa Y ? i 
a 
1886.] Zoology. 297 
determining’ lines of descent is thus presented. The enamel 
organ of generalized types it would seem furnishes groups of 
characters which are probably secondary in value (since the sev- 
eral parts of the organ indicate wide ranges of variation and of 
great adaptivity) to! those yielded by the modulations of the 
surfaces of the dentine-——Harrison Allen. 
An EXTRAORDINARY Human Dentition.—A gentleman living 
in Charles City, Iowa, recently exhibited to me the folfowing re- 
markable dentition. To name the teeth from their forms, the 
formula would be as follows: I. 8; C.4; Pm. 2; M.$%. By po- 
sition the formula would read thus: I. $%; C. +; Pm. right side 
2; left side, Cea) . 3. The first true molars in both jaws 
have a small accessory lobe on the inner side of the anterior 
inner tubercle. A brother of this gentleman has the following 
dental formula: I, 4; C.4; Pm.2; M.3. A sister presents the 
following: I. 3; C.4; Pm. 23; M.§. A grandmother has the 
incisors 3—£. D. Cope. 
ZOOLOGICAL News.—Echinodermata.—H. Ayers, who has studied 
the sphzridia of Echinoids both at Cambridge and Banyuls, 
asserts (Quart. Jour. Mic. Sci., Nov., 1885) that these organs have 
great specialization of parts, especially of the nerve-cells, an 
that, as before considered probable by Lovén, the evidence at 
present is in favor of the view that they have the combined func- 
tions of taste and smell. Sounds do not appear to affect the 
, while the spines and pedicellaria are at 
once affected, and the adjacent spines direct themselves toward 
the source of sound. During the Talisman expedition fifty-four 
Species of starfish were found, some from more than 4000 meters. 
Thirty-five of these species are new, and afford instructive com- 
binations of characters. 
Mollusca—Paul Pelseneer (Quart. Jour. Mic. Sci., Oct., 1885) 
describes the cephalic appendages of Clione, Clionopsis and 
Pneumodermon. From this it appears that all these genera have 
two pairs of tentacles, the posterior with eyes; and that Clione 
and Pneumodermon are also possessed of buccal appendages, = 
which in the latter genus are -provided with suckers, The tenta- 
cles are probably homologous with those of ordinary gastropods. 
——Professor Ray Lankester calls attention to the fact that sixty- 
ae The more simple forms of teeth, such as those of the molar series of the peccary, — 
Show scarcely any differences between the enamel and the dentine surfaces, and it eu 
may be reasonably expected that the test contrasts will be seen in the teeth which 
them. When in the position first named they re t the highest degree of special- 
attained by the molars of the pria Aii pepes exhibit a tendency toward 
x edea of the transverse ridge of the tapirodont type of tooth. When. 
i Paypomtion last named the cuspule described above leads to the oblique crest seen 
Bi Palzotheri r its allies. 
