12 BULLETIN 150, UNITED STATES NATIONAL MUSEUM 



Pyloric coeca. — Pyloric coeca are present in all the species except 

 Acantholiparis opercularis (cf. C. ectenes). The number varies in 

 Liparis from about 110 in L. antardica and L. liparis to 70 or more in 

 L. agassizii and other species. In the genus Polypera the coeca are 

 fine and thicldy matted about the pyloris and number about 300. 

 In the more specialized genera the average number of coeca is less. 

 This is readily seen by an examination of table on page 35. When 

 the number of coeca is not more than 10 they are arranged in a 

 single series which may not completely encircle the duodenum. In 

 Liparis the coeca are on the right side of the visceral cavity and in 

 the more specialized genera on the left side. This change of position 

 is due to a shortening and shifting of the U-shaped stomach. 



BrancJiiostegals. — The Liparidae have previously been described as 

 having six branchiostegals. This is true for all but Nedoliparis 

 and Lipariscus which have five, the interior one being absent in these 

 genera. 



PricMes.- — Scales are represented by two types of prickles termed 

 "thumb-tack" and "cactuslike" prickles. The former have been 

 found in three genera — Liparis, Careprodus, and Paraliparis. The 

 "thumb-tack" prickles consist of short spines with round, flat heads 

 which are imbedded in the skin. The spines are lost with the epider- 

 mis but leave shallow pits in the dermis which indicate their presence 

 in the specimen. These pits are easily seen on the thick-skinned 

 specimens of Liparis but are obscure on the thin-skinned species of 

 Careprodus. The "cactuslike" prickles are known to be present in 

 four species of Careprodus and probably will be found in other 

 genera. They consist of groups of spines arising close together in 

 the dermis and bear a close resemblance to some found in the Cyclop- 

 teridae. (See Jordan and Starks, 1895, pi. 94.) The number of spines 

 or prickles in each group may vary from 4 or 5 to 10 or more. 



Dorsal Jin. — In a number of the species the anterior dorsal rays 

 are set off from the remainder of the fin by a notch. This notch is 

 present in species of Liparis, Careprodus, Polypera, and Temnocora. 

 It may be hardly evident or may extend to the base of the fin. In 

 some species, such as Liparis dennyi, the dorsal notch is present in 

 some specimens and absent from others. 



The dorsal typically is connected to the caudal. In certain tide- 

 pool species the connection is short, not extending beyond the skin- 

 covered base of the caudal. The other extreme is found in Liparis 

 pulchellus, tessellatus, and owstoni, in which the connection is fully 

 three-fourths the length of the caudal. In Liparis the connection 

 with the cadual is usually abrupt and frequently notched. In the 

 typical deep-sea genera the connection between the dorsal and the 

 caudal is fairly constant, varying from 0.3 to 0.6 of the length of the 

 latter. 



