188 MAZATLAN TTNIVALTE3 



* 



Obdee LATEEIBEANCHIATA, ClarJc. 



Family DENTALLAD.^. 



Gexus DE^^TALIUM, Linn. 



The fullest account of tke animal of tlds remarkable tribe, 

 will be found in Clarh, Moll. Test. Mar. Brit. pp. 225—238. 

 It has only a faint analogy with Fissui-ella ; and differs so 

 much from even the most aberrant of the Scutibranchs that 

 the Order, proposed by Clark, is adopted. There are many- 

 points of analogy with the Lamellibranchiate Mollusca, and 

 some with the AnneUds. Individuals appear to be very rare 

 at Mazatlan, perhaps in consequence of the scarcity of For- 

 aminifera, on which these blind, almost headless creatures 

 voraciously feed. 



^i4. Dentalitjm LIBATUM, «. S. 



D. t. solidd, alba, tereti, liris longitudinalihus temiissimis 

 creherrime indiitd ; liris in juniorem circiter xii., in adultam 

 circiter xxx., acutis, haud ceqiialibus ; parum areuatd, aperturd 

 branchiaU simplici. 



One perfect, though rather small, specimen was found en- 

 tangled ia the byssus of Modiola capax ; fragments occurred 

 of a much larger size. Long.'^, lat.'Oll—'QQ. 



Sab. — Mazatlan ; off" Modiola capax, Cham« and Spondyli, 

 very rare ; Lpool Col. 



Tablet 879 contains the perfect specimen, a small do. wedged 

 in the mouth of Ti-i\'ia sauguinca, and a fragment of a large 

 one, '065 across. 



245. Dentalium hyalixum, Fhil. 



Zeit.f. Mai. I^i6, p. 55, no. 27. 



Tablet 880 contains a minute sheU of a hyaline texture, with 

 an opaque line running along the inner curve, which may be 

 accidental. It probably belongs to the above species des- 

 cribed by Philippi from Mazatlan, although that is said to be 

 "versus apicem tenuissime striata," while this, which is ex- 

 tremely young, is smooth. Long. '07, lat. "01 — "025. 

 Sah. — Mazatlan ; 1 sp. off" Spondylus calcifer ; L'pool Col. ' 



